Q45 driveshaft R/R

[elwesso]

I intend on figuring out a way on making the driveshaft as new (or at least not vibrating as much)... I cant do $500 for a driveshaft now (as i still owe money on the car), so if I can spend maybe $200 and make it good enough, ill be happy..

My theory is that the driveshaft is a hunk of metal, and there really shouldnt be much that would fail on the shaft itself..... Unless something actually strikes it and causes it to go bad.. The things that should go bad are the moving parts.....

I sent an email to Tim (timatt) here on NICO... He has a pristine 91 Q, and replaced his driveshaft last year... He was telling me that he thinks the reason for his vibration was the U joints.. They were apparently not smooth in articulating...

After a few hours of research and emails, Ive come to the conclusion that there are 3 common reasons that the Q45 driveshaft "fails"

1. Bad U joints at the differential flange2. Center bearing 3. Foam insulation inside comes apart, and thus you must replace the whole driveshaft.

I noticed that there are about 8 different part numbers for driveshafts... I hoping that they updated it in 94 so it is more "reliable" and the U joints and center bearing are bad, and I wont have to replace the shaft...

So, my plan of attack so far is to take the driveshaft out, take it to some driveline shop and have them replace whatever is needed (if U joints, or center bearing are bad)... However, if the driveshaft which ill put in from the old Q fixes it, ill just stick with that..... Since it seems like it may only take about 30-60mins to replace it, even if it doesnt fix it, its not a lot of labor that Ive lost... I will do the procedure in the FSM listed to measure the runout on both flanges, thus it should be better balanced.....

I will ask before I start on this... I attached a photo below.. Look at the circled area.. When i was taking the engine out, and the engine was lowered some, there was some deflection in this area.. It seemed to bend a little, but then it went back.. What IM wondering is if this will then ruin the driveshaft.. I will probably try it anyway, unless the driveshaft out of the old Q looks completely ruined... I hope I wont regret not taking better care of the old driveshaft.....

EDIT: Symptoms: Pretty much vibration free up to 60. At this point, it is present but hardly bothersome.. At 75 it gets really bad, then from there on out its not as bad but still bothersome.....

[squeefoo]

If you take it out, take it to a driveshaft shop. They'll run it on the lathe and see if it's tweaked, and give you the rundown on those "caulked" joints -I bet they can be replaced. Might be a charge for the lathe check, they should have a balancer too. You'll be amazed about the "no big deal" attitude they have in those places, just bring it in and let them tell you what they think. Used to go to one in Milwaukee all the time for stuff on the snow plow trucks and some shortening/rebuilding on toys/projects of mine.

[elwesso]

Thanks squee.. Im gonna have to find a place like that...

This may sound silly, but what kind of things to look for in the yellow pages... ? Ive never heard of a "driveshaft" shop before.....

[gniknave]

This may sound silly, but what kind of things to look for in the yellow pages... ? Ive never heard of a "driveshaft" shop before.....

Haha...there's a "driveshaft" shop in San Francisco, but I highly doubt it's car related

[elwesso]

Well i called a place in Indy called "patterson driveshafts" and they said that theyd be able to spin balance the shaft for $50, replace the bearing for $15 (plus the cost of bearing), and not sure on the U joints...

Looks like I should be able to get a good as new driveshaft for around $200, assuming that the U joints arent that expensive..