Clunk During Shifts

[drewusmaximus]

Hi again, 1995 525i 5SPD 283k


I noticed when I shift during take off there's a clunk in the rear during shifts. For example, I slowly went into first gear and the rear clunked. Then I shift to second and the rear clunked. Sometimes it may occur on third gear, depending on the agression of acceleration. I looked under the rear and I can't see anything out of the ordinary.
Any idea what might cause the clunking? I looked at the diff bushings and they seem ok.
Besides the clunking during shifts the ride feels fine.

Thanks in advance..

[jmile46]

Subframe bushings, diff bushings, csb in driveshaft. Have these ever been replaced?

[drewusmaximus]

I've had the car for about three years and I have not replaced anything in the rear yet. It doesn't feel like the CSB. I'll double check the rear again. I think the last time I posted a picture of the rear, I was told the shock bushings were shot and I should replace them. Not sure what the PO replaced but, the car is in good shape for it's age and miles.

[jmile46]

Well you wont be able to see condition of subframe bushings. Not really diff either. Id assume they were never done. Mileage is one thing but age degrades them too. I know my e24, I can move subframe by hand, telling me they are very bad condition. I guarantee diff bushings are bad too. My e34 needs diff bushings, when I put car into gear you can hear the diff move.

[drewusmaximus]

Maybe I can put a jack under the diff and lift the diff slowly and inspect the bushings for flex. Thanks!

[demetk]

If you are not planning on using good jack stands to support the car then that would be a very bad idea.

[moroza]

CSB vibrates when loaded at ~40-60kph long before any noise.
Subframe mounts are a heavy *thump* you can feel, and often comes with rear-end wander.
Giubo (not guibo) at the front of the driveshaft makes a medium-pitched clunk and may or may not vibrate.
CV joints can rumble and vibrate, and if flexed enough (rare in RWD use, common in FWD) will make click/pop noises.
Diff bushings aren't common failure items but I would imagine a medium-heavy clunk.
Rear subframe center mount is also uncommon and I would expect a heavy thump.
Driveshaft pilot bushing wears out and can cause vibrations, but never a noise IME.

Reminds me of a sign that my former shop had:

Labor Rates:

Squeak-squeak.......... $50
Click-click-click.......... $125
Click-click-clank......... $150
Clunk-clunk-thump...... $180
Whirrrrrr .................. $200
Hiss-sputter-cough.... $300
Thump-thump-thud.... $450
Bang-bang-bang........ $600
(Silence) ................. $1000
BOOM ..................... $Sit down first

[demetk]

[drewusmaximus]

It's a noticeable thump that I can feel during first and second shifts. Sometimes in third. If I shift very slowly, I don't feel the thump. Actually, it's not a clunk, it's a thump. There is no rear end wander but, there is a vibration type noise at the right rear wheel, driving over 55 MPH but, goes away when I press on the gas. Basically, the vibration type noise dissipates every time I give it gas but, it apparent while coasting.

[south42]

This sounds like subframe bushings. It is a pain to do. But there are write ups on how to do it with out the proper tool. Took me about 3 hours to replace both sides. As long as you have a sawzal and a floor jack you can do this job.

Andy

[jmile46]

The noise when coasting is completely unrelated. How olds your diff fluid? As for subframe bushings, there is a great diy on youtube. Just have a blowtorch( or heat gun) if you put back in oem bushings good luck. As for me I used power flex which were quick and easy to put back in.

[bigsixe34]

I’m putting my vote on subframe bushings as well. Sounds like the classic set of symptoms. Particularly the more pronounced clunks on lower gear shifts where you’re transferring the torque more swiftly.

[drewusmaximus]

Yes! The Australian guy using the yellow Poly bushing, with the torch! He has the 540 but the process is the same. He has good videos.. Haven't changed the diff fluid. For the past two months, the wife has been driving the car in town. Roughly three miles a day. And it's so cold up here in upstate NY, with no garage, it's difficult to work on the car. But, I'm just waiting for the temp to go up to 50 deg. When it does, Grandpa is having surgery..

[moroza]

Three mile cold trips are very hard on a car. Recommend taking the scenic route, maybe twice.

Sounds like subframe mounts. I've got a set of Meyle HD for sale. Otherwise see here.

[jmile46]

Ding ding. His video was extremely helpful when I did mine. Im also waiting for the warm weather here in Chicago so I can tackle this job yet again on my e24.

[theBMWbeast]

OEM 25966, $20 at Pepboys, and Harbor Freights Heatgun for $8.99 with coupon. If you had something the same size already, then this is a $10 job, sans poly bushings. Press out, lube bushings, press in. Once you get it takes all of 5 minutes each side. Hardest part for me was lining everything back up.

[drewusmaximus]

Got the heat gun from HF! Ordered the bushings (not poly). As soon as they come in, I'm getting dirty..

[fo3]

If you have rubber OEM style ones then you'll need to make a press (high tensile bolt and some thick plates), or buy/hire BMW's special tool.
You'll need some some lube to help press them in too (factory spec is circolight' but I don't think it's around any more so has been updated to ipc 'p80' rubber lubricant). Some people just use kerosene or mineral turpentine

Have a read of this thread https://www.bimmerforums.com/forum/s...mount-bushings

[south42]

Can also use a floor jack with chains rapped around the subframe as a press. Also use dawn soap as a lub, with the bushings put them in the freeze for a few days before hand to get them to shrink as much as possible.


Andy

[drewusmaximus]

Excellent idea. Never thought of that. Thank you all for the tips!!

[fo3]

I know some people use soap but it isn't recommended as you want something that evaporates away and doesn't hold moisture or leave a residue that gets slick when moist.

[drewusmaximus]

I have mineral turpentine. I can use that and the bushings have been in the freezer for days and will stay in there until this weekend when I replace the old ones. I purchased OEM bushings. I'm not worried about pulling them out, since I can put a block above the old bushing, apply heat with the gun, while jacking up the subframe. I'm worried about pushing in the new bushings. I know it's easy installing the poly bushings but, there's no good thread or video on how to install OEM bushings with common garage tools. I honestly don't want to buy the tool just for one use. I can check to see if the local auto parts store rents them but, I doubt it. I appreciate the suggestions on freezing the new bushings, using mineral turpentine, and wrapping a chain but, knowing my luck, I have a bad feeling I will be stuck with partially inserted bushings.

What else can I do in order to push the new bushings in? Thanks in advance..

[demetk]

[drewusmaximus]

Awesome! Wait! what do I do with the chain? What do I secure the chain to? it seems the chain prevents the subframe from rising while jacking up the bushing but, I don't know where to secure the chain.Thank you for the pic!!

[demetk]

Wrap the chain around the subframe and under the jack. Place the subframe bushing on the 4x4 and pump up the jack. Once the bushing is starting to go in straight connect the two ends of the chain together with a bolt and without play. You just built a portable press. Do you see the bolt in the first pic?