is this a motor/tranny mount issue?

TornadoRed

Top Post Dawg
Joined
Aug 3, 2003
Location
Saint Paul (ex-San Diego)
TDI
2003 Golf GL 5-spd, red; 2003 Golf GLS 5-spd, indigo blue; 2003 Jetta TDI wagon, Candy White
A couple months ago I had to replace the manual transmission, after a catastrophic differential failure. A local shop had a spare transmission case, assembled all the right gears, and the rebuilt transmission works great and shifts better than the old one.

At the same time, I had to replace the VR6 clutch plate because the old one was contaminated with gearbox oil. The G60 flywheel was cleaned up and reused.

Very soon after my Golf was back on the road, I noticed a vibration starting around 3700-3800 rpm. Previously I was able to rev smoothly to about 5000 rpm. So I was understandably concerned.

I went back to the local shop, they put the Golf up on the hoist, and found that the dogbone engine mount was in poor condition. They replaced it with an after-market or performance dogbone and the results were horrible. There was so much engine vibration being transmitted to the chassis, that it was unpleasant to drive. ASAP I went back and the shop installed an OE dogbone, and the constant vibration went away. But I still have the vibration at 3700 rpm.

I am not sure if this is related, but there's also a little bit of a vibration at around 1900 rpm in high gear -- not exactly lugging, but just above the point where lugging could take place.

I am wondering if I need to replace the other engine mounts, or the transmission mounts, or if the problem could be from another cause. Any suggestions? My Golf is running very well except for this single problem.
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
Was the transmission mount tightened while the car's weight was off the wheels? If so it may be pre-loaded a bit and that will cause this. You'll need a new set of stretch bolts to fix it since you can't re-use those....
 

TornadoRed

Top Post Dawg
Joined
Aug 3, 2003
Location
Saint Paul (ex-San Diego)
TDI
2003 Golf GL 5-spd, red; 2003 Golf GLS 5-spd, indigo blue; 2003 Jetta TDI wagon, Candy White
Was the transmission mount tightened while the car's weight was off the wheels? If so it may be pre-loaded a bit and that will cause this. You'll need a new set of stretch bolts to fix it since you can't re-use those....
I don't know but I should think that the Golf was almost certainly on the hoist when these bolts were torqued.
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
There's a decent chance the engine support left some preload on the bushings when the mount was torqued. It's pretty easy to do that and if you do you'll get some vibration from the engine into the frame of the car. It's also possible the bushings in the mounts are worn out.
 

Curious Chris

Top Post Dawg
Joined
Jun 11, 2001
Location
Pineview GA
TDI
Jetta Wagon 2003 RIP Rockford IL
Just for laughs move the front tires to the back. I was chasing a hard acceleration vibration on my car and I was ready to change the axles. Then spring came and I put on my summer tires and poof problem gone.

Just a thought as I remember you were running non VW rims on your car when we did the starter.
 

TornadoRed

Top Post Dawg
Joined
Aug 3, 2003
Location
Saint Paul (ex-San Diego)
TDI
2003 Golf GL 5-spd, red; 2003 Golf GLS 5-spd, indigo blue; 2003 Jetta TDI wagon, Candy White
Just for laughs move the front tires to the back. I was chasing a hard acceleration vibration on my car and I was ready to change the axles. Then spring came and I put on my summer tires and poof problem gone.

Just a thought as I remember you were running non VW rims on your car when we did the starter.
That was when I was still running my winter tires. Now I've got new Michelins on 16" VW alloys -- the vibration was present before and after mounting the new tires.
 

dieselboy04'

Veteran Member
Joined
May 2, 2011
Location
Va
TDI
05' Jetta TDI GLS 5spd
Pull your air box and make sure your gear case mount/motor mount is tight. I had one bolt hole strip out and the other was barely hanging on. It would vibrate off my panzer pan and drive me nuts.
 

TornadoRed

Top Post Dawg
Joined
Aug 3, 2003
Location
Saint Paul (ex-San Diego)
TDI
2003 Golf GL 5-spd, red; 2003 Golf GLS 5-spd, indigo blue; 2003 Jetta TDI wagon, Candy White
I want to check the transmission mount, but I still don't understand why this vibration only starts at a certain high rpm, 3700-3800. Why isn't it present all the time?
 

dieselboy04'

Veteran Member
Joined
May 2, 2011
Location
Va
TDI
05' Jetta TDI GLS 5spd
Mine was rpm specific as well. Mainly under a hard pull, but I never really took mine over 2500-3000 rpm.
 
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