Driveshaft support vibration with T56

[iaksa]

Hi everybody,

Recently swap my SC400 auto trans with T56 on my boosted M90 with E420C and my only problem is driveshaft vibration in the first gear,
just few seconds after releasing clutch. In the all others gears and high speed are ok. Looks like when driveshaft start rotation in the first gear it bents driveshaft and make high pressure on rubber support.
Initially I have problems with: loose driveshaft support, driveshaft support adjustment - add spacers, replace 4Runner trans mount with TransAm ones - now much better shifting, send to driveshaft shop to double check modification, balance again (two parts balanced together) - no problems, check driveshaft support bearing and rubber - no problem found.
Trans and Driveshaft shops suggested driveshaft support rubber piece to be replace with polyurethane.
I guess my questions are, Is it problem with driveshaft support only ? Something else to be checked ?
How easy is to replace driveshaft support ? Who can make driveshaft support rubber piece from polyurethane ?

Any other idea ? Thanks.

 

[spf_lexus]

Do your U-joints have any play?

 

[iaksa]

No, second time driveshaft shop check U-joints too

 

[spf_lexus]

hmm. My only idea would be the the center carrier bearings or trans bearings. I had an old 88 toyota pickup tha tvibrated like crazy unbder load. The center carrier bearings ended up looking like squares instead of spheres Lol. if you can rule out the driveshaft balance carrier and u-joints.. I would check into the bearings of the new manual trans. I would assume a trans bearing would cause vibration at certian speed as well. Also, maybe a bad pilot/throwout bearing?

 

[iaksa]

Thanks for quick reply ...
It happened only a few seconds (1.5-2 sec max) in first gear, if front wheels are turn full left or right the stronger vibration are - more load on driveshaft more vibration, also quick release clutch on 2.5-3k produce stronger vibration. Whole kit is brand new (Rush Import), new flying wheel, new pilot and throwout bearing ... before trans mount replacement (4runner with trans am) I feel vibrations closer to trans, after it's more around center support bearing. Trans is used 40k from 2004 Pontiac GTO, looks in very good shape. Trans mount is now more tight and shifting is better.

 

[gloverman]

On the Pontiac that the trans came out of does it run a rubber donut to link the driveshaft with the diff? I suggest having a good check as I know of another T56 with a similar vibration and it came down to the donut (vibration dampener) on the diff not present in the conversion. Cheers

 

[iaksa]

Not 100% sure about GTO set up, just quickly check some GTO forum, looks like stock is two piece with donut on the diff. My driveshaft is off SC300

 

[gloverman]

So yours doesn't have a donut on the diff?

 

[samsdad]

On the Pontiac that the trans came out of does it run a rubber donut to link the driveshaft with the diff? I suggest having a good check as I know of another T56 with a similar vibration and it came down to the donut (vibration dampener) on the diff not present in the conversion. Cheers

'04 Pontiac GTO aka Holden Monaro or VY Commodore Hardy Spicers (donut) at both ends with a CV joint at the centre bearing. Shudder in 1st at take off normally caused by a soft "donut" or driveshaft not correctly phased. Was common on "Commonwhore" fix was to either replace the "donut" or pull the C/V apart and correctly phase the driveshaft.

Check your engine mounts too as a soft or broken one will give much the same effect and also the stock 4runner gearbox mount aint the strongest thing. Worst case is they'd vibrate like hell at higher speeds.

Oh which clutch/Bellhousing set up are you using? That can also cause similar issues and you are only talking fractions of a mm there... A certain Surf does much the same but that will soon change

 

[iaksa]

So yours doesn't have a donut on the diff?

Mine has donut on the diff.

 

[iaksa]

'... also the stock 4runner gearbox mount aint the strongest thing. Worst case is they'd vibrate like hell at higher speeds.

Oh which clutch/Bellhousing set up are you using? That can also cause similar issues and you are only talking fractions of a mm there... A certain Surf does much the same but that will soon change

Currently I am using trans-am trans mount, when I replaced 4runners with trans-am trans mount make difference ...

I have kit from Rush Imports(Neil): organic twin plate, stock bell housing with adapter ...
http://rushimports.com.au/store/index.php?cPath=20&osCsid=be624add210e231c91906e1079e443de

 

[samsdad]

Organic clutch is like a switch. it's either on or off

 

[iaksa]

Just quick update.

Last week went to my tuner, put car on the lift, run under load (using breaks). Looks like it is not problem only in the first when taking off as I described. Vibrations happened in all gears between 1200 and 1500 RPM but less and less in higher gears.
Trans and engine are not moving at all, drive shaft badly vibrate where is shaft support.
We suspected may be engine and trans center line is not parallel with diff center line and SHOULD be.
Looks like three thinks should be checked:
1. SC300 drive shaft came in two pieces (disassembled before ship to me) - not sure if assembled on same way - orientation should be important
2. Rubber donut (orientation) connection with diff
3. Play with drive shaft support spacers (add some washers)

I can try above, just to see if make a difference, changing one thing at the time.
Will look for some "rear engine-trans-driveshaft-diff alignment" experts in my area.

Any other idea ?

 

[iaksa]

Just to close this thread, end up with damaged drive shaft support bearings, taking off drive shaft, compare with original SC300 manual, it was phased wrong, re-phased re-balance, change drive shaft support bearings, works now as expected