hey all, I posted this on TB, but in case that turns into a suck fest I wanted to get this down over here. The thread lasted about a month with ~85 replys.
Here's the original: http://forums.turbobricks.com/showthread.php?t=255788

I thought I'd post this up here, incase it helps anyone, and as a way to introduce my car to some of you Rally guys.

The highlights are there was a bad vibrations at a specific vhicle speed (not engine speeD), it wasn't the driveline, it wasn't the pinion angle, it wasn't the rear end, it wasn't the wheels... etc. I tried everything. Then I learned about bellhousing alignement. Anyhow enjoy.
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Those of you who know me know I don't easily ask for help, without bashing my head into the brickwall for hours. So it's will head hung low I ask for you advice. I haven't been able to figure this out out.

So here's the deal. Goldie, my '92 940 project car got a t5 swap last july and has been plagued with problems since.

Relevant parts list:
flat flywheel, 8.5" spec s2+ clutch kit - it's not rpm dependent anyhow
solid under-drive pulley
Solid rubber 740 motor mounts

Rebuilt T5 (also tried a second borrowed T5 which didn't change anything)
modified aw71 x-member
energy poly trans mount

62" (or what ever) 3" DOM tube driveline (balanced)
new fancy spicher 1330 rear u-joints
used mustang slip yoke and 1350 u-joint
no play in either u-joint

full Kaplhenke rear end (subframe, tq rods, ph bar)

freshly rebuilt 1041 rear end
new bearings shims and seals
axle shafts checked for balance and straightness

Pinion angle is set to 2.5 deg down at the trans and 2.5 deg up at the pinion. So they are equal and opposite with 2.5deg of working angle for the u-joints. I do not know how I can measure the side to side alignment, I'm just assuming that since it's in the center of the tunnel it's all good.
this is one of the sites i used to learn how to set a pinion angle:
http://jniolon.clubfte.com/driveline...nephasing.html

Vibration tests were done with car up in the air (on the suspension), wheels, brake rotors and e-brake removed. So it's just the axle, driveline, trans, and engine spinning. Road tests have the similar results, with 2 sets of wheels and tires.

The symptom:

At 3200 rpm driveline speed (~60mph) I get a strong driveline vibration. I can visually see the driveline move up and down as it spins, and using applying a scribe slowly to the spinning driveline it will chatter and mark about 2" of the circumference of the driveline.
I didn't setup a dial indicator to measure how much deflection there is.

The vibration is felt strongly in the car up to about 4600rpm driveline speed (~90mph) where is smooths out.

I'm running out of options, i've rebuilt the trans, the rear end, and replaced all the motor and trans mounts. I've tried several different pinion angle combos, including raising the trans so that it's pointing up, and lowering the pinion. The driveline has been back to the driveline shop 2 times and each time they tell me that's it's perfect and that it spins up beautifully. They don't however include the slip yoke in the balancing.

I'm going to have them install a new front u-joint and a new slip yoke tomorrow. With those replaced, I don't know where else to turn.

What have I overlooked? How likely is it that there is a lateral pinion offset, and how can I check that?

Thanks for the help guys. I'm real close to scrapping the 1pc and going to a 2 piece.

(wall of text crits your eyes for 4600dmg)


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The FIX:

As per Nathan's suggestion I checked out my bellhousing alignment.

First numbers were scary to say the least over .030 or 10x the allowed misalignment.
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5%20Swap/Photo440.jpg



I rearranged the dial indicator to be more accurate and measured that it was still .010 out, so more matterial removed.
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5%20Swap/Photo442.jpg

Getting closer:
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5%20Swap/Photo443.jpg

How I aligned it was to clearance the opening in the bellhousing and slipping the adapter down.
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5%20Swap/Photo444.jpg



A few more passes with the emery cloth, and a few more refittings and remeasurings I eventually got it close enough. The spec being passed around is .004" misaligned. I'm happy with .002"
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5%20Swap/Photo445.jpg


Since the adapter was no longer interference fit into the bellhousing again as per Nathan's suggestion I decided to pin the adapter in place by drilling and threaded 2 7/16" bolts through the bellhousing and into the adapter.

I used an end mill to make 2 flat spots on the bellhousing.
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5%20Swap/Photo450.jpg

http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5%20Swap/Photo449.jpg

Drilled and tapped some holes.
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5%20Swap/IMG_0628.jpg


And bolted it down:
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5%20Swap/IMG_0621.jpg

http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5%20Swap/IMG_0619.jpg


I also changed the tail housing of the T5 for another unit that had a significantly wider tailshaft bushing. The new bushing was only .750" wide where the old one from this other box was 1.25" wide so I figured it may help stabilize the slip yoke.

So that's the story, I got it all installed, dialed in 1.5deg of pinion offset on the driveline and ran it up on the jackstands. Ran real smooth well past 130mph will very little vibration at the problematic 65mph range. Put it on the ground and drive it, and god dam it drives like a regular 5 speed, not a car trying to shake itself apart. Simply amazing.

as always pics of my build can be found here:
http://s483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/

Thanks for reading.

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I like to play with cars, it's very inappropriate.

I would have just said to build it into a rally car that sees alot of rough roads and then you'd never notice the vibration.

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Grant Hughes

yea but aparently the 940 is the wrong Volvo to go Rallying in.

... or was the 940 just the wrong Volvo for everything?

Just teasing ya John

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I like to play with cars, it's very inappropriate.

A 940 is like 3.9167 times the best Volvo rally car.
Sure their big and ugly and lots of lesbians drive them, but doesn't that apply to all Volvos?
At least it's RWD.

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Grant Hughes

I have a feeling Mr Jardevall is going to prove the 940 is a fine car to build.

Insteresting.

Is that adaptor plate from Dale?

Quote
Gravel Spray
I have a feeling Mr Jardevall is going to prove the 940 is a fine car to build.

Fine car for a very aggressive driver.

(ya know--somebody who really will pitch it sideways)

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Quote
alkun
Insteresting.

Is that adaptor plate from Dale?

it's one of the older kaplhenke adapter plates. Nothing was really wrong with the adapter. The MS that opened up the bellhousing didn't get it prefectly centered so that when the adapter was pressed in it wasn't centered. Or the crank was a little offset in the block.

Anyway I'm so happy to have my Gold brick back. With a working manual now it's amazing. I've had the car for 10 years with a slush box, it's like a diferent beast with a shifter.

This is about as much offroading as I do:
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/940IMG_0255.jpg

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I like to play with cars, it's very inappropriate.