Jump to content
  • When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Rear suspension and brakes done, strange harmonic


golf02

Recommended Posts

I just took the beastie out for it’s maiden trip, performed the following:

rebuilt rear suspension, new bushings, new shocks, new (used) differential, rebuilt drive shaft (new center bearing & guibo) rebushed shifter platform, new urethane trans mount, when through brakes (new everything), detailed undercarriage (satisfies my OCD).

now I am picking up a strange harmonic towards the rear end under load. Pretty sure everything is lined up (center bearing preload etc). What am I missing gang?

11D993C4-DCF8-4C32-A264-CB2DC8C614C9.jpeg

7A60DE4A-164D-478A-B587-216598917458.jpeg

FBC92D57-B6CC-4650-8534-C99355AA9761.jpeg

87C663A4-FC81-4471-9C02-75DAE8AE8CA1.jpeg

395321CA-6D3D-4624-822C-EA7D61BB16A9.jpeg

Link to comment
Share on other sites

12 minutes ago, golf02 said:

new urethane trans mount

My money is on this; remember the exhaust is supported off the back of the transmission (with very little rubber); when you put hard urethane in there you get a pretty direct path of exhaust vibration transmitted to the chassis.  While I find urethane fine for suspension stuff; I strongly prefer HD rubber for engine and trans mounts.  Might be wrong of course, but one guess to get you started!

P.S. DAMN that underbody is CLEAN!!! Nice job, wows!

Edited by AustrianVespaGuy
  • Like 1
  • Thanks 1
Link to comment
Share on other sites

Start with the simple stuff like Vespa Guy said tranny mount, did you preload the center bearing? shift tower clear of everything, did you clock the drive shaft the way it was, exhaust not hitting rear cross member. You did so much making your car look fabulous the old what was the last thing I fixed standby is not going to work to narrow it down so just keep plugging away at it. 

If everybody in the room is thinking the same thing, then someone is not thinking.

 

George S Patton 

Planning the Normandy Break out 1944

Link to comment
Share on other sites

Looking at the license plate, have you considered an exorcism? 

 

In seriousness, while I don't have any firsthand experience with them, I've never heard much good about urethane drivetrain mounts for NVH or durability, so my money's on @AustrianVespaGuy's suggestion. 

 

-Dave

Colorado '71 2002

'17 VW GTI Sport
'10 Honda Odyssey Family & Stuff Hauler

Link to comment
Share on other sites

Wow, you can eat off that undercarriage.

That's an unusual exhaust setup, at least for me it is. Could those exhaust tubes be rubbing against each other? They are very close to the spare tire well, also. All that stuff moves and shakes while the engine is running and while you're driving.

image.png

Edited by JerryC

Jerry

no bimmer, for now

Link to comment
Share on other sites

The exhaust is pipes are welded together, it’s a vintage supersprint exhaust circa 1980’s ? It makes the most lovely sound. It’s been on the car for quite a while . But I am not sure I have got it back in the right way. As is with anything vintage it never works the same way twice.

Link to comment
Share on other sites

+3 on the tranny mount.  Replace with one from an E21 or Bavaria--much larger than the OEM '02 article, so it'll last longer and be stiffer than the original--without transmitting vibrations like a urethane mount tends to do.

 

mike

'69 Nevada sunroof-Wolfgang-bought new
'73 Sahara sunroof-Ludwig-since '78
'91 Brillantrot 318is sunroof-Georg Friederich 
Fiat Topolini (Benito & Luigi), Renault 4CVs (Anatole, Lucky Pierre, Brigette) & Kermit, the Bugeye Sprite

Link to comment
Share on other sites

When you mounted the diff, did you tug it backwards after installing the driveshaft?

 

I usually grab the diff, brace my feet on the car, and pull as hard as I can with the bolts

slightly loose.  

 

This seems to help a lot- the driveshaft doesn't mind slight tension, but left slack

or in slight compression, it can vibrate.

 

what I've found,

 

t

 

  • Like 1

"I learn best through painful, expensive experience, so I feel like I've gotten my money's worth." MattL

Link to comment
Share on other sites

Thanks for the tip on the trans mount and differential , spent the day cleaning the shop and floors so I can crawl sound underneath and not get all funky. Ordered Bavarian trans mount and will let you guys know what happens. I love this board, always someone around to help!

jay

Link to comment
Share on other sites

On 8/9/2020 at 6:29 PM, JerryC said:

 They are very close to the spare tire well, also. All that stuff moves and shakes while the engine is running and while you're driving.

image.png

Pretty close to the gas tank as well and no heat shield.... just sayin?

76 2002 Survivor

71 2002 Franzi

85 318i  Doris

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • BMW Neue Klasse - a birth of a Sports Sedan

    BMW Neue Klasse - a birth of a Sports Sedan

    Unveiling of the Neue Klasse Unveiled in 1961, BMW 1500 sedan was a revolutionary concept at the outset of the '60s. No tail fins or chrome fountains. Instead, what you got was understated and elegant, in a modern sense, exciting to drive as nearly any sports car, and yet still comfortable for four.   The elegant little sedan was an instant sensation. In the 1500, BMW not only found the long-term solution to its dire business straits but, more importantly, created an entirely new
    History of the BMW 2002 and the 02 Series

    History of the BMW 2002 and the 02 Series

    In 1966, BMW was practically unknown in the US unless you were a touring motorcycle enthusiast or had seen an Isetta given away on a quiz show.  BMW’s sales in the US that year were just 1253 cars.  Then BMW 1600-2 came to America’s shores, tripling US sales to 4564 the following year, boosted by favorable articles in the Buff Books. Car and Driver called it “the best $2500 sedan anywhere.”  Road & Track’s road test was equally enthusiastic.  Then, BMW took a cue from American manufacturers,
    The BMW 2002 Production Run

    The BMW 2002 Production Run

    BMW 02 series are like the original Volkswagen Beetles in one way (besides both being German classic cars)—throughout their long production, they all essentially look alike—at least to the uninitiated:  small, boxy, rear-wheel drive, two-door sedan.  Aficionados know better.   Not only were there three other body styles—none, unfortunately, exported to the US—but there were some significant visual and mechanical changes over their eleven-year production run.   I’ve extracted t
  • Upcoming Events

  • Supporting Vendors

×
×
  • Create New...