|
|
|
|
 |
 |
 |
BMW Garage | BMW Meets | Register | Today's Posts | Search |
 |
|
BMW 3-Series (E90 E92) Forum
>
Sonnax Zip Kit in 07 GM 6L45
|
 |
| 05-09-2018, 05:08 PM | #1 |
|
Second Lieutenant
 65
Rep 218
Posts |
Sonnax Zip Kit in 07 GM 6L45
I have a 07 GM 6L45R RWD. It started with the infamous 2-1 kick coming to a stop. Dealer updated the software but the problem gradually came back. Sometimes starting from a stop there was hunting in 1/2 as if it does not know which gear to be in. This appeared to be a side effect of the update -- solved one problem, made another worse
 I did not have hard shifts in other gears. There was also high fluid temperature and some sort of converter drag (behaving like high ATF pressure if you had experienced it before) which slowed the car down when letting go the gas. I think the high temperature likely resulted in the early demise of many rubber gaskets, as well as exhibiting the "jet engine" sound of the cooling fan often. The Sonnax Zip Kit solved them I would say 90% of the time. There are no longer the 2-1 kick but sometimes you do feel the downshift. The starting gear hunt is much better but not completely gone, just a lot less. I imagine if I also did the ATF pump area updates then that might help a great deal. The engine bay seems cooler and I hardly hear the "jet engine" any more. Besides, the car coasts easier and farther. So overall I am happy. Depending on the revision and the amount of wear, your results may be different. The next thing is to learn how to update the program in the transmission.  And many thanks to the OP for posting the ATF filter DIY for the 6L45. It has helped me getting started with this transmission. (https://www.e90post.com/forums/showthread.php?t=573490) I took some pictures during the installation of a Sonnax Zip Kit in my 07 GM 6L45 valve body. I did not take a complete set of pictures particularly during messy valve body disassembly/reassembly. Here they are: The instructions that came with the kit. You can find the pdf version on their website. The kit runs about $270. https://www.sonnax.com/parts/3505-zip-kit  The parts inside the zip kit. All the little bags came in a large plastic bag. Some of these bags were meant for the ATF pump area. Since I did not remove the transmission, I used only the parts that went into the valve body.  Valve body separator plate GM 24245720, about $11. If you have a plate earlier than the "Early 2nd Design", then update the separator plate to this one according to the instructions. Check with Sonnax if you are unsure. Sold under the AC Delco brand.  Looking at the ID notch cut into the separator, mine was between the "Early 1st Design" and "Early 2nd Design" (Figure 4 of instructions), given that my separator had only one notch. The 24245720 I ended up using was the "Early 2nd Design" with 3 notches, probably 2 revisions newer. Obviously GM had a lot of teething pains with this. IMO, the "Early 2nd Design" should really be called "Early 4th Design" given it got extra 3 notches since the 1st.  Here is a picture of the valve body. I have an early version of the valve body with exhaust ports like the 6L80 example (Figure 3 of the 8-22-17 Sonnax instructions). The casting numbers however did not match those stated. My upper had a casting number of 1590, and the lower 6351. A call to Sonnax suggested that I use the updated separator plate for the "early" valve body. It worked out well. These casting numbers were often seen on BMWs. Good grief, it was an Aisin valve body!  Maybe this was the problem? Those with VWs, Porsches and Aisin transmissions might know.  It is very important that you use the correct separator for the generation of valve body in your transmission. If you are unsure, check with Sonnax.  Especially for those with 328xi and X3, you might experience a no-reverse problem and maybe together with no-forward. This is likely caused by a broken manual shift valve. The transmission might go into limp mode and allow you to drive to the shop. Or just have a flatbed transport it to a shop. Below is a picture of the Sonnax manual shift valve for the 6L45. In the OEM part, the blocky portion of the shift valve is connected to the shaft with a weak plastic dowel pin! This was a bad design. And this dowel pin can break easily, leaving you stranded. Perhaps the updated $25 BMW part works better, but if you are doing all the work dropping the valve body, consider the Sonnax anodized aluminum $60 manual shift valve. You do not want to dig back in again because of a small piece of plastic! https://www.sonnax.com/parts/4522-manual-valve-assembly  This is what it looks like with the valve body dropped. In the left of the picture you can see the 4 round tube seals still in the transmission case. They came together on a metal holder plate. In the Zip Kit there were metal plugs you can install in the case and the valve body to mitigate the fluid leakages likely to occur there. I used a small hammer and some blue Assemblee Goo to carefully hammer them in place. I heard you can also use Vaseline if you do not have Assemblee Goo. To the right you can see other fluid passages between the case and valve body. There are two other seal assemblies that should be replaced as the rubber takes a heat set. Near the upper right you can see the filter seal still in there. IMO this was also a bad design. I had to use a plastic 1/2" garden sprinkler valve extension 6" long (what I had laying around). Put it against the seal, turn it up sideways and out it popped. The ZF filter/seal design is sooooo much better. At least we are lucky not getting whole Aisins, unless it is a 1-series Mini clone. ha ha ha You can see that the blocky part of the manual shift valve has a slot. The green circle marks the pin that should sit in there so when you shift the lever, the manual valve will move correctly along with the cam.  The GM 24238925 kit has a filter plate and case and sleeve seals, about $25. There is another kit without the filter plate, for about $14. I think this is the right part number, do verify as I used parts from a rebuild kit ($$$, pictured below) before I found this.  Well, in the beginning I did some searches for the plate and seals but did not find this kit in time. Therefore what I picked up was a much more expensive rebuild kit in order to locate these parts. I never liked to reuse old rubber parts in there given that heat and age hardens rubber. So change them if you have come this far! The 6L45-50 use shorter center tubes (the 4 round ones in a row). The 6L80-90 use taller ones. Make sure you get the right ones.  The valve body was held in the transmission with 6 Torx-Plus bolts. This helped differentiate them from other bolts holding the solenoids or two halves of the valve body together. Using a less popular bolt type was not a smart move. I was not sure why GM could not just use allen head bolts. Most of us already have allen bits or torx bits right? If not then check Harbor Freight when on sale. Now I had to buy a Torx-Plus set online. According to the instructions, a standard 11/32" 6-point socket should work with care on the 6 Torx-Plus bolts holding the valve body in place, if you do not have the specified Kent Moore DT-48285 "External Torx-Plus" socket. One Kent Moore socket costs about $25 plus shipping. No way I am getting just one socket when the entire Lisle 83100 set is about the same price. The Lisle set runs anywhere from about $25 to $35 plus shipping online. http://www.lislecorp.com/divisions/p...s/?product=747  Here is the valve body in the pan. Draining and refilling ATF every year will keep the fluid crystal! Walmart's Supertech Dexron VI will work at about $5+ a quart. or use Valvoline Maxlife ATF at $18 per gallon. What I should have done was remove the detent spring under the manual valve first (yellow arrow). It would make installing the valve body into the case easier later. On install, make sure the manual valve sits correctly against the shift cam pin in the transmission so when you shift the manual valve will move correctly with it (yellow arrow points to the bolt holding the detent spring). The red arrows show filter ports for the solenoids. I used low pressure (30-35 psi) compressed air to carefully blow off the debris. Wear suitable safety goggles when using compressed air! Cleanliness is very important. Do not allow dirt, debris and lint to get into the valve body during assembly. The bores should be clean, and when dry, the valves should drop straight down to the bottom of the bore on gravity alone. Some use Bench Buddy abrasive bore brushes. I did not need any. https://superiortransmission.com/pro...uperior-bb100/  And the electrical connector shell (the "mechatronic sleeve") will get 3 new o-rings/seals. In the picture I showed it as pulled from the transmission, before putting on the new seals.  The fluid webbing inside the valve body. There were also several check balls in the zip kit that are more durable than the white plastic ones from GM.  The valves and springs that came out. I threw away the check balls already, sorry. 3 of them had visible wear (dull surface), and one was visibly smaller. In one of the videos I linked later, one of the check balls can get worn down that it will plug a hole in the separator, causing you to lose a gear.  Notice the wear on the end plug. Usually shiny crescent moon shaped as the end plug vibrates in the bore, allowing pressure leaks. Sonnax gives you end plugs with o-rings to help better seal them.  Old filter plate and separator plate (one notch). The old filter plate looked clean, but the rubber was most likely compressed. It is recommended that you always replace it if you need to work on the valve body. I did.  And it gets a new filter (usually comes with a new seal), sold together about $7. A new pan gasket about $12. The gasket is supposedly reusable, but I always change it. Depending on your driving habits maybe change the filter every 30-60K miles. I refilled with 6 qts of Dexron VI with the engine off, using a funnel and PVC tube into the dipstick port on the right side of the transmission. Yes the whole 6 qts and maybe a little more to help set the fluid level later. There is a black plastic plug that can be removed where the dipstick tube was, on the right side of the transmission. Then I started the engine, shifted through the gears, and then removed the check plug to set the fluid level. It was much faster this way. I never bothered with checking the fluid temperature, just with the powertrain at room temperature after many hours of cooling off.   My special tool for removing the filter seal. This was all I had on hand and it worked! Way easier than tapping, deforming the shell in and pulling it out with pliers. Check out how ZF seals filters. That is the right way to do it.  Place the threads against the seal and pry by turn the pipe up 90 degrees.  The BMW factory drain plug is made of flimsy aluminum. I replaced it with a GM steel one with gasket for about $3. ACDelco 24234212. I am not sure why BMW dropped the perfectly good OEM steel one for an aluminum plug.  IMO the right way to seal a filter (ZF OEM):   HTH Last edited by labrador; 05-14-2018 at 05:56 PM.. |
| 05-09-2018, 05:09 PM | #2 |
|
Second Lieutenant
65
Rep 218
Posts |
Here are some of Sonnax's other fixes for the 6L45, typically requiring special fixtures and drill bits. You can look at them to see in detail the symptoms they help solve, and maybe gain insight as to which parts of the transmission are giving you problems. ttps://www.sonnax.com/units/306-6l45
The zip kit contains many of the fixes in tool-free form. That is the purpose of zip kits. From the looks of the descriptions below, the fixes should work out even better with the ATF pump area parts replaced I believe. Pressure Switch Rebuild Master Pack 124740-28K (Comes with installation tools. There is another kit without the tools, if you already have them.) https://www.sonnax.com/parts/3754-pr...ld-master-pack Help cure: Pressure control out-of-range codes Slips, flares & bind-ups Failsafe mode Erratic TCC apply Harsh shifts Shift codes Boost Valve Kit 104520-01K https://www.sonnax.com/parts/3069-boost-valve-kit Help cure: Low line rise in Drive Soft shifts Burnt clutches Line Pressure Booster Kit 6L80-LB1 https://www.sonnax.com/parts/3057-li...re-booster-kit Oversized Converter Feed Limit Valve 104520-11 https://www.sonnax.com/parts/1701-ov...ed-limit-valve Helps cure: High TCC slip RPM Code P0218 Code P0741 Overheated converter Inadequate lubrication Excess converter pressure Oversized Pressure Regulator & Boost Valve Kit 104520-07K https://www.sonnax.com/parts/3070-ov...oost-valve-kit Helps cure: Erratic line pressure High line pressure Low line pressure Clutch slippage Harsh shifts Low cooler flow Burnt clutches No cooler flow Overheated transmission Converter concerns Pressure Regulator Valve Kit 104520-03K https://www.sonnax.com/parts/3068-pr...ator-valve-kit Helps cure: Erratic line pressure High line pressure Low line pressure Clutch slippage Harsh shifts Low cooler flow No cooler flow Overheated transmission Soft shifts Converter concerns Center Support Seal Kit 104740-14K https://www.sonnax.com/parts/3525-ce...pport-seal-kit Helps cure: Burnt clutches Loss of lube oil Overheating & reduced lube feed Checkball 10000-08 https://www.sonnax.com/parts/1689-checkball Imidized Plastic, .250" Dia. Clutch Select Valve Spring Kit 104740-02K (Mid 2010-Earlier) https://www.sonnax.com/parts/1703-cl...lve-spring-kit Helps cure: Code P0751 1-2-3-4 Clutch burned 3-5 Reverse clutch burned Cruise control disabled Compensator Feed Regulator Valve Kit 104740-09K https://www.sonnax.com/parts/1705-co...ator-valve-kit Helps cure: Harsh shifts Downshift clunk Bump shifts Flare shifts Bind-up Burnt clutches Overheated fluid O-Ringed End Plug Kit 104740-23K https://www.sonnax.com/parts/1707-o-ringed-end-plug-kit Contains 6 Plugs & 9 O-rings Helps cure: Shift concerns Burnt clutches Oversized AFL Valve 104740-12 https://www.sonnax.com/parts/1706-oversized-afl-valve Helps cure: Solenoid performance codes Clutch failure Wrong gear starts Harsh shifts Soft shifts Oversized Clutch Boost Valve 104740-01 https://www.sonnax.com/parts/1702-ov...ch-boost-valve Works in any of 3 locations Helps cure: Shift quality is not load sensitive Clutch pressure solenoid codes Burnt clutches Delayed engagement Harsh shifts Slide shifts Slip codes Slips & flares Oversized TCC Regulator Valve Kit 104740-07K https://www.sonnax.com/parts/1704-ov...ator-valve-kit Helps cure: Code P0741, P0742 High TCC slip RPM Overheated fluid Failsafe mode Harsh shifts Harsh TCC apply Loss of fuel economy Last edited by labrador; 05-10-2018 at 05:33 PM.. |
|
Appreciate
1
e90yyc2426.50 |
| 05-09-2018, 05:10 PM | #3 |
|
Second Lieutenant
65
Rep 218
Posts |
Here are some videos on the 6L45:
Broken 6L45 manual shift valve. Do not let the shop sell you an entire reman transmission because of a little valve!! Notice another 1590 casting number in the second video. The stuck check-ball problem on the 6L series (video on 6L80). 4:50 into the video: [This is why the Sonnax imidized check balls are good to have! As I said, I found 3 with wear and 1 visibly undersized. That was probably the #1 check ball (I did not track locations taking them out  )]If you want to rebuild the pressure switches: Disassembling the 6L45: The valve wear that happens in the ATF pump area (6L80). This is why I believe I might solve the other 10% of the remaining shift problems had I pull the transmission and replace these. But no, not planning that in the foreseeable future. You can also search up the 6L80 as they are very similar. There are vidoes on pulling automatic transmissions from BMWs as well on Youtube. This looks quite involved. Last edited by labrador; 05-11-2018 at 05:13 PM.. |
|
Appreciate
1
e90yyc2426.50 |
| 05-09-2018, 06:49 PM | #4 |
|
Major General
 2191
Rep 5,007
Posts |
I didn't know the 2-1 hard kickdown was indication that things were wearing out. Good to know!
Also, great descriptive post. Should be a sticky! These transmissions aren't getting any younger and likely lots of people will be have issues as these age. |
|
Appreciate
1
labrador65.00 |
| 06-08-2018, 03:31 PM | #6 |
|
Second Lieutenant
65
Rep 218
Posts |
@e90yyc -
Looks like there might be some misunderstanding. Mind you I do not even know if I used the right terms!  Anyway just trying to clarity:- The rubber VB-to-transmission seals are all very easy to put in. Even somewhat loose. They seal by the VB fully seating against the transmission. As ATF needs to pass through these rubber tubes without leaking to give you pressure. This was what I was referring to when I described to check that the wire harness or whatever else is not caught between the VB and the transmission to prevent these tubes from sealing fully. If you go back in check before/while/after you loosen and remove each piece. * The rubber VB-to-transmission seals: https://images.oreillyauto.com/parts...13_primary.jpg - The filter seal is the one with the interference fit. I use a socket fitting the diameter of the seal's flat lip to hammer it in. There is no way this seal is going in by hand pressure! Again, not the best design. - Solenoids (TECHM assembly). These are not the (spool) valves. I have NOT disassembled the TECHM — did not dare to touch it myself as I do not understand this assembly. The only thing i would do is to clean the filter ports as described in my Zip Kit post with 30 psi air. TECHM assembly with solenoids, the chunk of plastic careful not to crack: https://static.summitracing.com/glob...5873_ob_ml.jpg - Spool valves or just "valves". These are the valves removed from the halves of the VB to be replaced by new ones from Sonnax. These are the ones that should move freely without sticking in the VB bores. Check the orientation and location on the Sonnax instruction sheet. An example spool valves: https://d2q1ebiag300ih.cloudfront.ne...g?v=1519933046 - Reviewing the videos again. In the 6L80 video by Hiram, 45 minutes in, he talks about a stuck valve causing pressure loss. Sounds like a familiar possibility? Anyway here it is again: |
|
Appreciate
2
e90yyc2426.50 StradaRedlands4950.50 |
| 04-01-2021, 09:43 PM | #9 |
|
Private
 10
Rep 53
Posts |
I'll add some of my own personal experience to this great post. Thank you labrador for the great write up.
I had some issues with my 328xi transmission overall just shifting poorly but one particular problem was when in manual mode, downshifting from 3-2 I would get a nasty flare up. I tried to reset adaptations but it didn't really change anything. For reference, I have 185,000kms and only changed the fluid once at 120,000kms. I installed the zip kit into my 328xi and only installed the valve body parts. These transmissions are extremely common in a lot of GM vehicles and trucks and these zip kits are used by many in the transmission industry with lots of success. Installing the additional parts that go inside the bell housing will yield even better results, but it requires a lot more work that I wasn't going to do. I asked above with no response but as a follow up if ever someone else is doing this, I did not end up changing the separator plate. This is not something that needs to be changed every time according to what I've read. But your mileage may vary. For the filter plate (different than the separator plate), this has some rubber seals and needs to be replaced every time. For the fluid, I used OE AC Delco Dex 6. Previously I've used Valvoline Maxlife and had good success with it, but it smells so bad I didn't want to use it again. I also changed the filter and and transmission pan gasket with OE BMW parts (lifetime warranty at FCP Euro). After installing, I reset the adaptations but the actual transmission learnings. Reseting the adaptations regularly through ISTA is not the same as actually relearning the transmission. There are some other posts that go more in depth but basically in Tool32 in the GS1912 module, I ran these commands. STEUERN_ADAPTS_RESET_PLANT STEUERN_ADAPTS_RESET_WITHOUT_TCC STEUERN_TCC_ADAPTS_RESET For the first couple of kilometres the car was shifting absolutely horridly, flares and roughness all over. After driving a bit (maybe 30km) the transmission relearned properly and the car is shifting great. As OP mentioned, I think this resolved about 90% of my issues and would probably have been perfect if I installed the additional parts than go inside the bell housing. The transmission no longer kicks and most importantly the 3-2 downshift issue was resolved. Anyone with any transmission issues on these cars should definitely follow the great guide posted above by labrador Great work! |
|
Appreciate
1
e90yyc2426.50 |
| 08-26-2021, 01:39 PM | #10 |
|
Lieutenant Colonel
 1082
Rep 1,675
Posts |
BTW, when working on the valve body, DO take the time to rebuild the pressure switches and think about using a new manual shift valve. The rubber seals and flimsy discs for the pressure switches should to be replaced (along with other tube seals and whatever parts you are working on) if the valve body is removed.
Here are my notes and pictures on the pressure switch rebuild, solving the 1-2 slip-bump and general poor shift quality with 2-3 and 3-4 shifts. https://www.e90post.com/forums/showp...6&postcount=12 |
|
Appreciate
0
|
| 09-10-2021, 05:00 AM | #11 | |
|
New Member
0
Rep 5
Posts |
Quote:
|
|
|
Appreciate
0
|
| 09-10-2021, 05:22 AM | #12 |
|
Major
 
1188
Rep 1,457
Posts |
Yesssss. Ive tried to find other people with this issue and no one ever knows what I'm talking about. I like to be a cool guy and do a little power slide when making right turn. Typical from a stop (or under 5mph) in 1st - floor it- turn right-slide the back end out- try to shift to 2nd- get a weird slip/bump thing
|
|
Appreciate
0
|
| 09-10-2021, 10:23 AM | #13 |
|
New Member
0
Rep 5
Posts |
[QUOTE=AlpineE93;28018252]Yesssss. Ive tried to find other people with this issue and no one ever knows what I'm talking about. I like to be a cool guy and do a little power slide when making right turn. Typical from a stop (or under 5mph) in 1st - floor it- turn right-slide the back end out- try to shift to 2nd- get a weird slip/bump
It sounds similar to what mainbearing posted originally. I'm definitely down to tear into the trans to fix it but I gotta get some better instructions haha. I'm a moron  |
|
Appreciate
0
|
| 09-10-2021, 05:47 PM | #14 | |
|
Lieutenant Colonel
1082
Rep 1,675
Posts |
Yes, 1st gear going to 2nd. Worst when cold. It made some people think the transmission was just doing the warm up, but NO, that was not the case. It would rev like 2500-3000 and then bang! Yes, like shifting into gear while giving gas.
I thought it was something more major like clutches and such. But no, it was just these sh*tty pressure switches in a sh*tty transmission. Before you can fix it, try warming up more before you drive off. And be light on the gas for a mile or so and usually the slip-bump will be softer. I linked a Sonnax instruction (Zip Kit) on removing, disassembling and reinstalling the valve body in the earlier post. Check that. It was a messy, ATF dripping and flowing mess. LOL but I was glad I did it. BTW, since yours is a 07, do the Zip Kit too.    Quote:
Last edited by mainbearing; 10-19-2021 at 08:35 PM.. |
|
|
Appreciate
0
|
| 09-10-2021, 08:30 PM | #15 |
|
Major
1188
Rep 1,457
Posts |
So is there a down side to NOT installing this kit? Like is the trans just going to randomly explode on one of these bump shifts? It seems like alot of work that I don't particularly have the time and space to do right now. And I'd I'm being honest my trans dosent really do it all that often.
While we are on the shitty GM trans topic... some times when I'm in manual mode, and I go to accelerate (flooring it) let's say shifting from 2nd to 3rd it will some times prematurely shift into 4th (in manual mode) on its own. |
|
Appreciate
0
|
| 09-11-2021, 11:27 AM | #16 | |
|
Lieutenant Colonel
1082
Rep 1,675
Posts |
From Sonnax's website (https://www.sonnax.com/parts/3505-zip-kit), the kit reduces critical oil circuit pressure losses. And the symptoms include:
Burnt clutches Delayed engagement 3-4 Bump Inadequate lubrication Low pressure Slips & flares Soft shifts TCC apply & release concerns TCC codes There may not be a down side for not installing it if you do not feel the problems mentioned above in shifting. However, with the problem description I would think the kit will make the transmission last longer if you enjoy this car and plan to keep it around for a while, particularly if you are dropping and disassembling the valve body to change out the hardened leaky seals which is where most of the work is, IMO. Other members had said that the E90 is the last real BMW sports car. There is a pressure regulator valve you will not be able to get to without dropping the transmission however, but at least the rest will get updated. As far as your skipped gears in manual mode, one possibility would be the computer will try to select the gear suitable for the speed and may be overriding. The other is that the pressure switches help the computer decide shift points and shift calibrations, and may be thinking 4th would be the right gear then. I am not sure if those are actually the problems, just guessing. Yup, overall the 6L45 is just not a good transmission compared to the ZF 6HP. I guess BMW had to cut cost somewhere, including using cheap plastics in the cabin so they can spend on complex coolant flanges that fail. IMO the dash plastics in the newer ones are even worse. Just all the wrong cost decisions in all the wrong places. Quote:
Last edited by mainbearing; 09-11-2021 at 11:26 PM.. |
|
|
Appreciate
0
|
| 09-11-2021, 11:58 AM | #17 | |
|
Major
1188
Rep 1,457
Posts |
Quote:
There is some what of a delay when shifting in manual mode, when you up or down shift its not instantaneous like a DCT or a new trans. I'm thinking that when I attempt to go into 3rd, I'm shifting a half second too late. So basically it shifts twice... if that makes sense. |
|
|
Appreciate
0
|
| 09-11-2021, 05:32 PM | #18 |
|
New Member
0
Rep 5
Posts |
[QUOTE=mainbearing;28022743]From Sonnax's website (https://www.sonnax.com/parts/3505-zip-kit), the kit reduces critical oil circuit pressure losses. And the symptoms include:
Burnt clutches Delayed engagement 3-4 Bump Inadequate lubrication Low pressure Slips & flares Soft shifts TCC apply & release concerns TCC codes I hate to hijack the thread but I can't PM as I'm a new user and this seems to be the best forum I've found yet with very active users. But what I'm experiencing really only happens in DS mode. If I run it in drive the car doesn't really do the slip bump or act funny. Now with me just thinking how these things work with pressure etc "I've never worked on a auto transmission or even seen past valve body's, only dog box manuals" it almost seems as pressure is not able to be maintained at a higher rpm causing the tiny slip/bump. When it short shifts I really don't have a issue. Hopefully this can help point you into the direction of if this trans is trash or if your fix will help. Also the magnet had VERY little debris on it. Oil was just dirty. No burnt smell. I took a bunch of videos the other day driving and mutilated the exhaust so you can hear the rpm vs tach movement and trans engagement. |
|
Appreciate
0
|
| 09-11-2021, 09:59 PM | #19 |
|
Lieutenant Colonel
1082
Rep 1,675
Posts |
AFAIK, DS holds lower gear longer and allows the engine to rev higher. The gear changes are supposedly faster which might also mean higher ATF pressure is used.
I occasionally use DS in highway passing because the 6L45 is otherwise sluggish. I would not try a quick start at the traffic light against a Civic or Corolla for sure because the BMW will not win. LOL A transmission shop can do vacuum tests on valve bodies to look for pressure leak points. However if everything works in D, maybe yours does not have a problem but just the way these junky 6L45s shift? Last edited by mainbearing; 09-11-2021 at 11:26 PM.. |
|
Appreciate
0
|
| 10-18-2021, 04:29 AM | #20 |
|
New Member
0
Rep 5
Posts |
Here are some of Sonnax's other fixes for the 6L45, typically me again butchering the fourms haha.
So I got into the zip kit, waiting for 2 gaskets. Everything is going well. Only issue is, how do I install the 4 inserts into the valve body and transmission housing? They are a very tight interferencefit and I feel like I'm going to breaking sombody beating them into place.. I've though about doing the heat and cold install on interference stuff but just rather would ask the pro. |
|
Appreciate
0
|
| 10-18-2021, 01:22 PM | #21 |
|
Lieutenant Colonel
1082
Rep 1,675
Posts |
I hammered those carefully into place, all 8 pieces with a 4-oz hammer. I think Sonnax meant that, otherwise there would be pressure leaks from under them and out from the ends of the rubber tubes.
Follow the valve body reassembly instructions carefully and observe all torques and sequences. |
|
Appreciate
0
|
 |
| Bookmarks |
|
|
