Parts Catalog Accessories Catalog Tech Info Tech Forums
 
Follow Pelican Parts on Facebook Follow Pelican Parts on Twitter Follow Pelican Parts on Instagram Follow Pelican Parts on YouTube Follow Pelican Parts on Pinterest Follow Pelican Parts on Tumblr
  Search our site:    
View Recent Cars  |   Cart  | Project List | Order Status | Help    
Bookmark and Share

Pelican Technical Article:

Replacing your Transmission Mounts

Talent:

**

Applicable Models:

BMW E36 3-Series (1992-99)
101 Performance Projects for Your BMW 3 Series

This article is one in a series that have been released in conjunction with Wayne's new book, 101 Performance Projects for Your BMW 3 Series. The book contains 272 pages of full color projects detailing everything from performance mods to timing the camshafts. With more than 650+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any 3 Series owner's collection. The book was released in August 2006, and is available for ordering now. See The Official Book Website for more details.

Check out some other projects from the book:

One of the most common parts to deteriorate on the BMW is the engine and transmission mounts. The rubber that is contained within the mounts becomes old and brittle, and doesn't perform a good job of isolating the drivetrain from the rest of the chassis. Old, worn out motor and transmission mounts can cause shifting problems because the drivetrain is no longer firmly held in its position. One sign of this failure mode is the gearshift knob jerking backwards under hard acceleration or difficulty selecting gears during cornering. A visible sign that the motor mounts need replacing is the appearance of cracks in the rubber of the mounts. The rubber will deteriorate over the years and need to be replaced, even if the car has relatively few miles on it.

The transmission mounts are easier to replace than the engine mounts, and are very similar on both the E30 and E36 BMWs. A transmission mount bar is bolted to the rear of the car and supports the transmission. Begin by jacking up your car and placing it on jack stands. Now, place a jack under the transmission to support the weight. Then, carefully remove the transmission mount bar from the car (Figure 1 and Figure 2). You may have to bend the heat shield slightly out of the way to access the bolts that mount the transmission bar to the chassis. Close-up views of the old transmission mounts are shown in Figure 3, Figure 4 and Figure 5.

Remove the old mount by removing the nut on the underside of the mount bar (Figure 6). New mounts are shown in Figure 7, and are simply bolted in place of the old ones. There is a boss on the bottom of the mount that needs to line up with a notch on the transmission mount bar. This boss/notch combination prevents the transmission mount from rotating.

Stock BMW transmission mounts are not known for their performance or reliability. The purpose of the transmission mount is to isolate the chassis of the car from vibration that the transmission will transmit during normal driving. The transmission is connected to the engine, and has a tendency to twist and turn as the car accelerates or decelerates under heavy braking. If the transmission mounts are flexible and sloppy, then there may be a misalignment of the transmission with respect to the chassis of the car. This may cause what is commonly known as a miss-shift or in laymen's terms a "moneyshift." A mis-shift will sometimes cause the driver to accidentally shift from a high gear to a much lower gear and over-rev the engine. An over-rev is very damaging to the engine and typically results in the valves hitting the tops of the pistons and bending.

One solution is to use the early style BMW 320i transmission mounts. They are thicker, they have a tendency to flex less than the stock ones, and for the most part they are a bolt-in application. Another solution is to use better designed transmission mounts and brackets. I recommend the ones produced by UUC Motorwerks. The standard mount is shown beside the UUC mount in Figure 8. These new and improved mounts isolate vibration, but perform a better job at keeping the transmission correctly aligned with the chassis. In addition to the UUC transmission mounts, I also recommend the UUC Tranny Mount Enforcers (TMEs, shown in Figure 9).The TMEs hug and constrain the transmission mount and reduce the deflection of the amount under vigorous driving. The addition of the UUC mounts and the TMEs are probably the best insurance you can provide to prevent expensive mis-shifts.

The upgraded UUC transmission mounts are available in black or red.The black versions are tailored to street driving - the red ones are designed for track or autocross use. Figure 10 and Figure 11 shows the red UUC transmission mounts installed on the transmission mount bar. Grease up the inside of the TME prior to installation, to minimize chaffing of the mount (Figure 12). The TMEs are installed on the top of the transmission mounts, beneath the transmission mounting flange (Figure 13 and Figure 14). The flange from the transmission mount should fully protrude through the TME as is shown in Figure 15.

The completed mount assembly is shown attached to the transmission in Figure 16 and Figure 17. The transmission shown in these photos was out of the car for a clutch job. When installing the mounts back into the car, tighten up the bracket to chassis bolts first. Then lower the transmission onto the bushings and tighten the top nuts, securing the transmission to the bar.

When you are finished, you should feel an improvement in the shifting of your car, and the drivetrain vibration should feel a little tighter and less sloppy. If you would like to see more technical articles like this one, please continue to support Pelican Parts with all your parts needs. If you like what you see here, then please visit our online BMW catalog and help support the collection and creating of new and informative technical articles like this one. Your continued support directly affects the expansion and existence of this site and technical articles like this one. As always, if you have any questions or comments about this helpful article, please drop us a line.

Figure
Figure 1

Figure
Figure 2

Figure
Figure 3

Figure
Figure 4

Figure
Figure 5

Figure
Figure 6

Figure
Figure 7

Figure
Figure 8

Figure
Figure 9

Figure
Figure 10

Figure
Figure 11

Figure
Figure 12

Figure
Figure 13

Figure
Figure 14

Figure
Figure 15

Figure
Figure 16

Figure
Figure 17

Bookmark and Share
Loading...
Comments and Suggestions:
AndrewThePlumber Comments: cannot go from first to second gear while under way, not problem sitting still. Could mounts cause this too, its an 94 3251
September 3, 2014
  Followup from the Pelican Staff: Could be a worn transmission. It woudln't hurt to inspect the linkage and mounts. - Nick at Pelican Parts  
april Comments: My car when I put gear no4 it start vibration
August 27, 2014
  Followup from the Pelican Staff: Check the driveline for binding u-joints or faulty bearings. - Nick at Pelican Parts  
Mike Comments: Where is the vibration absorber part #24701142019 located on a 98 318ti automatic trans?
December 22, 2013
  Followup from the Pelican Staff: It is a bolt on damper to absorb vibrations. If I remember correctly, it bolts through the transmission mount.- Nick at Pelican Parts  
96 Bmw 328is Comments: Can't get the drivers motor mount upper nut off anyone has any advice?
December 14, 2013
  Followup from the Pelican Staff: Try a crows foot on a long extension. - Nick at Pelican Parts  
danlau Comments: I have a 1995 BMW 525i E34. Base on the part list, there seems to be 4 transmission mounts, 2 front and 2 rear. Is that correct? Do you have any instructions to replace the transmission mount for E34?

Thanks,
Daniel Lau
October 4, 2013
  Followup from the Pelican Staff: I thought there were only two on your model. It would be similar to the vehicle in this tech article.
Give our parts specialists a call at 1-888-280-7799. They can help you find the right part. - Nick at Pelican Parts
 
saneesh8 Comments: Where exactly i support the transmission with a floor jack? Under the big pan with a wood block to spread the weight?
July 31, 2013
  Followup from the Pelican Staff: Under the pan is fine, as long as you spread the weight out. If you look at the way a transmission jack is constructed, it is made to support under the pan, with arms that go up on the sides to add support and stability. - Nick at Pelican Parts  
drew_e30is Comments: I Have a 91 E30 318is and apperently the trans and motor have shifted forward. The trans wasnt even sitting on the mounts. How can I shift everything back to fit the new mounts. Im also replacing the motor mounts.
Any help would be greatly appreciated.
April 14, 2013
  Followup from the Pelican Staff: If you lift the engine from the top, using a hoist or engine jack, you should be able to slide it back. if it gives you trouble. Remove the driveshaft, this should allow the engine and transmission to move freely. - Nick at Pelican Parts  
bmwbeginner Comments: I have a 1998 bmw 328i automatic and I'm trying to replace the transmission mounts but can't see anyway of getting the nuts off of the top of the mounts.
December 29, 2012
  Followup from the Pelican Staff: There is a bracket across the body of the car that the trans mounts bolt to. Support the transmission with a jack and remove the bracket and as you lower the jack the transmission will slowly drop and expose the upper nuts you want to get to. Just be careful you don't damage the flex disc since you still have the driveshaft attached - Nick at Pelican Parts  
318i fan Comments: I was wondering this too Also I used a couple of 2x4 under the transmission oil pan and slowly cad carefully lift the tranny. Since it is end part of transmission so it holds the partial weight well.
December 29, 2011
  Followup from the Pelican Staff: Transmission jacks are made to support the weight of the transmission under the trans pan. If you spread the weight evenly it will be OK. - Nick at Pelican Parts  
318i fan Comments: I have a same question as Jean-Luc. I removed tranny bar but there's not enough room to remove upper bolts. Exhust pipe and catalyc converter etc block the way. I believe we might need some narrow style tools.
December 29, 2011
  Followup from the Pelican Staff: Yes, sometimes the bolts can be difficult to remove. I recommend a set of swivel sockets - they work great for getting into tight spots.- Wayne at Pelican Parts  
Aaron Comments: Any suggestions on how to support an automatic transmission? You can't simply put a jack under there because of the pan.
August 13, 2011
  Followup from the Pelican Staff: Transmission jacks are made to support the weight of the transmission under the trans pan. If you spread the weight evenly it will be OK. - Nick at Pelican Parts  
Rvi Comments: I have 3161 compact model 97 automatic I changed already the 2 engine mounts and 2 transmission mounts but the vibration still the same when the car idles in drive or idle in reverse,the rpm also goes down to 6 or nearly 7. Is there any other vibration absorbers fitted in my car that I need to replace?
June 9, 2011
  Followup from the Pelican Staff: Your engine might have a misfire tha feels like a vibration. Check to see that the engine is running well, no misfires. if the engine is running well, check that the exhuast is not making contact with the body. This could cause a virbation as well. - Nick at Pelican Parts  
DTM Comments: For everyone considering the UUC street trans mounts black ones which are advertised for no additional vibration. I tried 3 or 4 different installations of them the correct way, and still had vibration. Just be advised that they are very finicky. Some people have luck, others dont.
February 12, 2011
  Followup from the Pelican Staff: Indeed, I'm not a terribly huge fan of aftermarket or "racing" mounts, as they typically do translate more vibration into the cabin of the car. Most people who install them thinking they will improve performance are turned off by the excess vibration. I would recommend that if you do install them, that you keep an open mind and be prepared to possibly remove them again at one time. - Wayne at Pelican Parts  
sunny Comments: I have a 96 bmw 318ic. When the car idles in drive, there is a lot of vibration and I can even see my hood shaking. If i shift it into neutral or reverse, the vibration goes away. When the car is moving, the vibration goes away completely and my hood doesn't shake, are these my motor mounts?
December 25, 2010
  Followup from the Pelican Staff: Yes, I would check your drivetrain mounts. This would include the engine mounts and the transmission mounts too. Lift the engine up from underneath with a floor jack and see if there is a lot of play in the engine before the car starts to lift. If yes, then your mounts are probably shot. This also might be a dual-mass flywheel beginning to fail as well. - Wayne at Pelican Parts  
Jean-Luc Comments: The last step is: "Then lower the transmission onto the bushings and tighten the top nuts, securing the transmission to the bar." I assume this means that those nuts should have been loosened as the first step before the transmission is supported by a jack, right? Also, are special wrenches needed for these nuts or will a regular ratchet wrench work i.e., is there enough clearance?

Thanks in advance for your help and best regards,
November 29, 2010
  Followup from the Pelican Staff: Yes, you need to loosen the nuts in order to replace the mounts. I don't recall needed any special tools - a typical set should suffice. - Wayne at Pelican Parts  

Check out some other projects from the book:


  Search our site:    

View Cart & CheckOut | Project List | Order Status |  Help    

 

[Home] [Customer Service] [Shopping Cart] [Privacy Statement]
 [Contact Us] [About Us] [Shipping] [Map to our Location]

Copyright © Pelican Parts Inc.

Page last updated: Fri 9/19/2014 12:34:05 AM