Early G50 drive shaft upgrade

[DrewQ45]

Put an end to my vibration woes Friday. Finally installed a junkyard 94’ driveshaft which has a considerably more robust rubber surround for the centerline bearing. The 35-55 mph vibes are virtually all gone now (although I would not be the best judge having growing accustomed to living with them.) I would highly suggest going this route for anyone having driveshaft issues.

For a quick history... about a year ago I had my transmission replaced with a Jap takeout. When the mechanic removed my original driveshaft, he loosened all the bolts on the Guibos (rubber donut) up by the transmission tail instead of pulling the 4 bolts on the flange and yanking it out from the rear. That’s a big no no as the FSM instructs one to never touch these bolts. I’ve lived with the vibration until now but it had started worsening. I had gotten my hands on a few 90-93 shafts but ripped the aged and fragile rubber surround on each and every one during install. Take it from me.. it’s best to have a helper when installing…. one to get it aligned and the other to make sure the centerline bearing bracket does not undergo any excursions and rip the rubber. With the 94 shaft, the rubber is much more supple and flexible, not to mention the fact that it’s about double the amount of rubber of the earlier models. It’s also much cheaper than an aftermarket shaft and should work better.

As you’ll see detailed in coming pictures, I’m not even sure if I lined up the shaft properly, yet, the difference is amazing. The car feels like it should once again. I want to make sure I have aligned this thing properly since I’m a little confused regarding the markings mentioned in the FSM.

Whats up the photopost gallery being disabled?
Modified by DrewQ45 at 2:06 PM 10/3/2006

[VJ1]

Please keep us updated. I have the same vibrating issue on my 94 now, and considering buying a rebuilt shaft for $398.00. The center support bearing is also available for $151.00, but I dont know if I trust replacing just the support. I've heard that it should not be tampered with.Vandi

[Q45denver]

Is the updated OEM replacement part for the 90-93 the same as for the 94-96?

[elwesso]

Is the updated OEM replacement part for the 90-93 the same as for the 94-96?

any driveshaft OR center bearing you get will be the redesigned 94 design. if you have a 90-93 you will have to buy the brackets, if you have a 94 you wont have to buy the brackets....

the powertrain industries driveshaft i got had an even beefier center bearing!!!

[redmanfx]

Powertrain Industries has your driveshaft. It's good and they have never had one come back from a Q. 800-798-4585 is the number to them.http://www.driveshaft.com/catalogs.htm

I stand by them!

[PopPop]

Powertrain Industries has your driveshaft. It's good and they have never had one come back from a Q. 800-798-4585 is the number to them.http://www.driveshaft.com/catalogs.htm

I stand by them!

Wes returned his and got another one!

[elwesso]

Wes returned his and got another one!

no i didnt....

[bullittandy]

Driveshafts are something where the addage (sic?) "If it ain't broke..." pays off. Seems like every driveshaft I've ever dealt with is never the same afterwards. I'm afraid to even look at the one on my 97 for fear of introducing vibes.

[PopPop]

no i didnt....

Didn't U say one time that you were returning it and it was under warranty for no charge.

[66mgb]

Hey Red, or anyone else in the know - does Powertrain offer a Nico discount?

I'm about due for a replacement also for my '92. From 0 to 30, I have a slight vib.

I think I'm going to install new transmission and engine mounts while it's on the rack.

I'll tackle the rear bushings at a later date - maybe w/ a 4.08 install....

[Q45tech]

Most people dealers] don't take the 5 hours necessary to test the 3 positions on the road [measure vibration levels and frequency] and to shim the center bearing correctly.

Finding a smooth road to start is difficult as are getting the tires and brakes perfect, so they don't mask or confuse the measurements.

Most don't have access to the vibration test set.

[DrewQ45]

Most people dealers] don't take the 5 hours necessary to test the 3 positions on the road [measure vibration levels and frequency] and to shim the center bearing correctly.

Finding a smooth road to start is difficult as are getting the tires and brakes perfect, so they don't mask or confuse the measurements.

Most don't have access to the vibration test set.

Dennis, if you remember our conversation about driveshafts, just wanted to let you know I had no trouble with the length of it. I think you said something about the 94 + being either too short or long for earlier G50 due to TCS?

I did no shimming, however I did remove the original spacers (thick washers). The 94' comes with built in spacers built onto the bracket.

Hey folks, whats up with the gallery? I need to upload some photos. Do I need to find another host? The FSM pic you saw in my first post was a direct attachment.
Modified by DrewQ45 at 1:28 PM 10/3/2006

[DrewQ45]

Guess I’ll just attach pics to single posts for now…

The FSM details shaft alignment with companion flange (differential) using markings found on each. The problem is, each shaft I’ve come across has multiple markings. I’m confused as to which marking is considered “A” on the diagram. As you can see in the pics, the shaft has a long horizontal bar marking, then a white dot up near the U joint. What would be considered “A” on this shaft? I used the long horizontal white bar but I’m starting to think it’s the white dot.

..Drew…


Modified by DrewQ45 at 12:23 PM 10/3/2006

[DrewQ45]

"A" is questionable. Here you can see the white bar marked on the shaft and the white dot to the right of "G3". The companion flange has a white dot showing (B) and the end of my wrench handle is pointing to the secondary flange marking(C).


Modified by DrewQ45 at 12:13 PM 10/3/2006

[Jeff Williams]

Those look right on to me. Like I know anything......

[Q45denver]

"any driveshaft OR center bearing you get will be the redesigned 94 design. if you have a 90-93 you will have to buy the brackets, if you have a 94 you wont have to buy the brackets...."

My quote button doesn't work anymore. I had someone install a new OEM shaft on my 1990 a year ago. I'm sure they didn't replace the bracket unless it came with the shaft that I got from Joe.

[DrewQ45]

Guess I'm alone on this one?

[DrewQ45]

Okay, genius idea.... If anyone has their Q currently on jack-stands or plan on going under one anytime soon, please observe the driveshaft alignment with markings and report back in this post. Pics would be super.

TIA

....Drew.....

[elwesso]

Drew, you just want the line up the lines on the driveshaft and on the companion flange as best you can.

Ideally, one would measure the axial and facial runout so that you dont have to mess wtih the 4 possible orientaitons... Then just line it up wiht the line on the driveshaft and hope its right....

but, if all your powetrain related rubber (new transmission mount, new motor mounts, new diff bushings) arent new, then its hardly worth messing with....

The short story: you have it aligned as best you can. The problem with the alignment marks, is that they were made for the SPECIFIC driveshaft and diff combo.... Mixing and matching probably isnt ideal...

Powertrain industries says it doesnt matter what orientation you use on the companion flange, they told me it wont make any difference either way.... FWIW.

[Q45tech]

Sure it does with the proper vibration level test set you can see 3db voltage peak differences as you select different position.

Really difficult to just feel which is the best position as the road/tire vibrations cannot be repeated accurately on the same stretch of road at exactly the same speed. Therefore I test on a rack with wheels off ground.

http://www.babcox.com/editorial/us/us50126.htm

http://www.babcox.com/editorial/us/us50014.htm

[elwesso]

do you usually jack the wheels up so that the axle shafts are parallel instead of angled? Not sure if that would cause other vibrations...

[DrewQ45]

Final prognosis....I'm soooo happy with my used 94' driveshaft!!!! Not even sure if I lined it up perfect but I can detect no vibration at any speed so I'm happy!!!

I got my hands on another 94' drive-shaft this weekend thinking I might keep it as a spare, but I can't foresee anything going wrong anytime soon.

It's in it's complete form (rubber donut bolts never pulled) but it's not pretty and would probably benefit from a little sandpaper and black spray-paint to get rid of the oxidation. It has the beefy centerline bearing and the rubber is still supple and pliable. I checked the U joints and they move pretty smoothly and "notch" at the normal range of distention. Would let this unit go for $100 + shipping and would even be willing to clean it up some if anyone is willing to take a chance on it. I say "take a chance" because I have never tested it, however it looks to be in the same condition as the one I just installed.

.... This is much cheaper than aftermarkets which sell in the $350 - $500 range. It's even cheaper than buying a new centerline bearing alone ($150 avg) and having to pay extra $$$ to install and balance it only to get smaller vibrations. I've seen older (pre-94) shafts with the puny centerline bearings selling on Ebay (a rarity) for $150 or more + ship!

I'll post this in the classifieds soon but thought I might start here as those interested in driveshaft issues would probably be taking a read here.

..Drew....

[redmanfx]

Hey Red, or anyone else in the know - does Powertrain offer a Nico discount?

I'm about due for a replacement also for my '92. From 0 to 30, I have a slight vib.

I think I'm going to install new transmission and engine mounts while it's on the rack.

I'll tackle the rear bushings at a later date - maybe w/ a 4.08 install....

I don't think they do. Call and see.

Drew..... There was a reason I didn't put a 94 DS in my 92, but I can't remember what it was, so good luck with it. I just remember everyone telling me not to. I think it was the fact that it was "used" maybe??, It sure makes it an easier option for 90-93 owners if it works out for you . I don't think I would want to install a used drive shaft though.

[DrewQ45]

I don't think they do. Call and see.

Drew..... There was a reason I didn't put a 94 DS in my 92, but I can't remember what it was, so good luck with it. I just remember everyone telling me not to. I think it was the fact that it was "used" maybe??, It sure makes it an easier option for 90-93 owners if it works out for you . I don't think I would want to install a used drive shaft though.

I try not to listen to the big spenders too much. Most here would install a used engine or transmission if it came down to it. A drive-shaft consists of a few moving parts and a steel shaft and takes half an hour to replace. Can't see why anyone wouldn't want to install used and save big $$$. It's a no brainer for me. I have no problem keeping this shaft as a spare, just thought someone else might be tired of the rumbling from beneath and not get raped in the process.

...Drew...
Modified by DrewQ45 at 10:51 PM 10/9/2006

[VJ1]

Drew, you've got mail !