My butt's vibrating (driveshaft?)

[91QAZ]

After reading many posts and archives here I think I need to replace my driveshaft, but before I spend the money, I'd like to bounce a few things off you guys first. I read w/ great interest Wes' 70 mph vibration post. I have a vibration too, but mine's a little different. Almost ALL of the vibration I feel is in the seat, and is present at just about every speed.

I have a 91 Q (non-active) with 91K and 32K on a new transmission (replaced by dealer - I ASSUME they replaced the rear transmission mount too(?)). I haven't had the car on a lift, but when driving I don't hear any noise from the center bearing or differential. Original driveshaft and center bearing as far as I can tell. I just purchased the car with stock BBS 15" wheels with cheapo tires (Visa in front and Dayton in rear(?)) that were balanced at dealer 3,500 miles ago. I plan to replace these with 17" Michelins on '00 Maxima SE rims soon. But I REALLY dont THINK my vibration is wheel/tire related because it does not get worse at a certain range of speeds and then go away like unbalanced tires/wheels usually do. And I don't feel it in the steering wheel very much like I do when I need a tire rebalance - It's primarily in the seat.

Here's what I feel, at about 15 mph the seat starts to vibrate slightly - not much, but it's there. I can really start to feel it in earnest at 35 - 40 (in third gear). Then the shift into 4th and NO change in the vibe (so it's not the 2250rpm harmonic). It stays there pretty constant up to at least 105. It SEEMS to be a little worse when accelerating, and SEEMS to be a bit better when coasting down (decelerating) in neutral, but these are not big differences, and may be attributible to my own insanity. This is not a huge vibration (my wife doesn't even feel it, or attributes it to road imperfections), but I feel it all the time and it's driving me nuts .

Based on all of this, I'm about ready to buy an OEM driveshaft. I looked in the FSM (Thanks to Wes) and found great info on the driveshaft R&R, but very little info on diagnosing a bad driveshaft or center bearing. Is there a common driveshaft/bearing diagnosis that I have missed in all these posts? Is it worth replacing the bearing first or just doing the driveshaft and bearing at the same time. I'd DIY the job either way. I'd sure appreciate a sanity check and any other input on this issue. Thanks guys.

[elwesso]

This leads me to believe that my driveshaft isnt bad..... Because i have no vibration up to 70.....

Anywho.. I thought I remember someone saying you can balance the driveshaft, like you would wheels and tires......

Anyway, I have a few TSBs on vibration that are applicable to your model year.. Email me again... I can email them to you... They are valuable information...

The TSBs give a lot of good info about vibraitons and other things since they are based on real world driving...

[91QAZ]

Thanks Wes, The TSB's provide good info on phasing the propshaft and also mention a "improved balanced propshaft assembly". Part number 37000-60U99. I assume that this is the propshaft I want to replace mine with, since it is "improved", correct? Dennis, any thoughts?

Thanks,Tom

[Q45tech]

The only one you can buy new. With 4 possble phases I can take hours days to find the correct one for your speed ...........don't even try it without Michelins and perfect wheels because you'll get confused unless you just measure shaft runout and not the ride at speed feel.

Hard to tell by feel you really need a vibration amplitude analyser.

[91QAZ]

Thanks Dennis - this is sounding less and less like a DIY job. I wish I were closer to T3. What tool do I need to measure shaft runout? How much$? If I understand correctly, short of measuring runout, I'd be left installing it and drive testing it. If no good, try next phase and repeat - possibly 4 times until I determine which phase has least vibe, right? Point taken re: the wheels and tires. Thanks again, I'd be over my head without this board (maybe I am anyway(?))...

[elwesso]

Tom

Look in the PD section... You just need a runout gauge (not sure what theyre called), and im not sure how much they cost... however theyll come in handy..

I would assume the FSM using the runout gauge would give you nearly perfect results... I suppose you could try both but that would take forever.. Gotta pay the price for perfection...

What kind of wheels/tires do you have.....

[91QAZ]

Wes, I bought the car with the 15" BBS wheels and mismatched tires (Visa in front, Dayton in back(?)), but plan on installing 17" wheels from a '00 Maxima SE and Michelins.

I need to do more research on runout gauges and vibration amplitude analyzers. I've never used either before, but sounds like I may be learning in the future (if the are cost effective, that is).

I read PD - 5, 6, and 7, and it SOUNDS like I would only need to check runout on the companion flange if it is removed, otherwise I should be able to use the existing B and C marks (?). I don't see where it describes coming up with mark A on the first propeller tube, maybe the first tube comes pre-marked with "A" (?).

What I don't know at this point is what is included in a new driveshaft assembly. It seems that it should include both tubes (already connected and phased at the companion flange) - everything from transmission to differential, but maybe I'm wrong. IF the assembly includes both tubes, I guess I still may need to deal with phasing between the second tube and the final drive (differential). Maybe that's what Dennis is referring to. If I'm wrong then maybe the new driveshaft only includes the first tube, and I'd need to phase the first tube to the companion flange.

I'll call Joe tomorrow and learn more about what is actually included in the driveshaft assembly. The education continues...

[squeefoo]

Tom

Look in the PD section... You just need a runout gauge (not sure what theyre called), and im not sure how much they cost... however theyll come in handy..

It's a dial indicator; you can get a fairly OK one for around $50.00 even cheaper, but blow around 50. Try Northern Hydraulics or better yet; Enco. If you get one for less, you'll wonder if you should've bought the better ($50) one, so just get it, (includes different tips and extensions). Plus like Wes says you can check rotors and hubs -and even small non-rotating linear movements like pulley bearings.

[elwesso]

Wes, I bought the car with the 15" BBS wheels and mismatched tires (Visa in front, Dayton in back(?)), but plan on installing 17" wheels from a '00 Maxima SE and Michelins.

I need to do more research on runout gauges and vibration amplitude analyzers. I've never used either before, but sounds like I may be learning in the future (if the are cost effective, that is).

I read PD - 5, 6, and 7, and it SOUNDS like I would only need to check runout on the companion flange if it is removed, otherwise I should be able to use the existing B and C marks (?). I don't see where it describes coming up with mark A on the first propeller tube, maybe the first tube comes pre-marked with "A" (?).

What I don't know at this point is what is included in a new driveshaft assembly. It seems that it should include both tubes (already connected and phased at the companion flange) - everything from transmission to differential, but maybe I'm wrong. IF the assembly includes both tubes, I guess I still may need to deal with phasing between the second tube and the final drive (differential). Maybe that's what Dennis is referring to. If I'm wrong then maybe the new driveshaft only includes the first tube, and I'd need to phase the first tube to the companion flange.

I'll call Joe tomorrow and learn more about what is actually included in the driveshaft assembly. The education continues...

I think the tires are contributing.. Ive never heard of both of those, but they kinda sound like crappy tires (no offense)

I dont know what that analyser thingie is but I have a feeling it would be easier for you to take the car to dennis who knows how to use all this crap then for you to try and figure it out... The data is only as good as the person who can interprit it!!!

Youll be safe using just the dial indicator..... I want to buy one for myself too sometime...

The driveshaft includes both tubes..... I checked it in the FSM.....

The A mark is factory.....

[91QAZ]

Cool, good to know both tubes are included. The tires are indeed crappy, and they need to go. I wish I were closer to Dennis, I'd gladly pay someone who I KNOW will do the job right. I may indeed be buyig a dial indicator as well...

[911/Q45]

How far are you from San Diego? Jerry Tucker does T3 quality work.

[91QAZ]

About 6 hours away. Unfortunately, not very time effective. If I planned right, I could do it this summer and spend the weekend at the beach while the Q was being worked on ...

[elwesso]

Tom.. I found this thread and thought you might enjoy it...

http://www.nicoclub.com/zerothread?id=55358

Seems like our problem could be related to the center bearing

[texasoil]

Replacement center supports (bearing included) for The Q45 (and all other Nissan,volve, etc cars are available at low cost from PowerTrainIndustries.comQ45 part # is 1280-70Its the rubber support ring that fails. U-joints also get 'notchy' or stiff and can easily be loosened up by working them and/or tapping with a hammer to unstick the thin 'needle bearings' from the greas so they roll rather than skid. This will cure maybe 90% of 'driveshaft vibration' problems at a small fraction of new shaft cost.

[elwesso]

GREAT information!!!

Also, if your OCD, ive found a place that can spin balance them for like $50...

[redmanfx]

Powertrain Ind. tn 714-901-3611

red

[elwesso]

How do they powertrainidustries driveshafts compare to OEM???

I hear a lot of times the foam inside gets messed up causing the vibration...

[91QAZ]

Wes, great thread! I need to get under there and look at my center bearing. I may be able to get under the car next weekend.

I asked Joe if I could buy a center bearing seperate from the d-shaft and he said, no it was all one assembly. Maybe I misunderstood him, but from this thread it sounds like the center bearing can pretty easily be replaced without replacing the d-shaft, yes?

Anyone have R&R advice on doing just the center bearing?

[elwesso]

I looked in the FSM and parts book and the center bearing is a seperate part... There is a procedure in the FSM about this...

You need to have a shop press to press to put in the new bearing... I talked to a driveshaft shop around here that it costs $15 to press in a new bearing, plus the cost of the bearing..... I want to find out how much a new driveshaft from powertrain industries is... Look in the yellow pages for a driveshaft shop... Should be one close to you

THe OEM part number for the center bearing is 37521-6P025

If I can get a new driveshaft from powertrain industries for about $200-300 ill go that route, otherwise ill get a new bearing and have the driveshaft balanced...

[91QAZ]

Wes, I checked out the FSM procedure - looks like maybe with the pullers and presses required it may be worth replacing the whole assembly if the cost difference is not too much.

I found the Powertrain Industries website, but no prices were posted. I'll have to call them this week. wholesaleimportparts.com listed a remanned d-shaft at $361 plus a $60 core charge, and they pay for shipping of both the new shaft and the core.

[elwesso]

Good info tom....

Ill call this other place tomorrow and report back..... Shipping both ways is golden because shipping is EXPENSIVE.. Driveshaft is VERY heavy.....

[elwesso]

The PTI driveshaft was $455 or something around there.. includes a 1 year unlimited mileage warranty and shipping both ways... The guy was VERY nice...

$60 core charge, so basically it comes down to about $400.. FOr that,it might be worth the extra $100 for an OEM one...

Basically the one that Tom listed is $100 less.....

EDIT: A lot of places Ive called basically order from someone else who rebuilds them (like this place above.), instead of rebalancing and replacing stuff on the shaft themselves... im going to do some more research on the ones Tom listed...

EDIT2: I looked at the website Tom gave, and basically this looks very comprable to what PTI has to offer.. free shipping both ways, and a 1 year unlimited mileage warranty...

[gloucester Q]

91qaz-did you ever get a driveshaft? i did a search of the web before i dug up this thread and also came up with the wholesaleimportpart.com site. wondering if you did it how it worked out? thanks. -randy

[jamesmost]

i have the PTI drive shaft and i have no problems w/it if u purchase it thru a shop it will only cost $275 which is righteous. i forget how long i have mine, as well when u replace ur rear sub frame bushings w/suspension tech urathane it pitches the angle of the drive shact perfectly

[gloucester Q]

hmm, i just got off the phone with everythinginfiniti and they quoted in the low 500's for a new shaft, which, at that price delta almost seems silly to pass up. want to get down to the dealer first though and verify that's what i need, and if so, if anything else. argh, and the free shipping on orders over 75 bucks ended today...

[elwesso]

hmm, i just got off the phone with everythinginfiniti and they quoted in the low 500's for a new shaft, which, at that price delta almost seems silly to pass up. want to get down to the dealer first though and verify that's what i need, and if so, if anything else. argh, and the free shipping on orders over 75 bucks ended today...

Ive talked to a lot of people about this and personally i wouldnt recommend the OEM.. Get the rebuilt one (no better as far as warranty) and you get serviceable U joints and it eliminates that stupid flex disc.....

[91QAZ]

Glouster,

Yep, I got the Powertrain Industries DS and have had it installed for a few months now. The Q is nice and smooth now - except over 80 mph. Now I need to look at rear subframe bushings and try to narrow down my >80 vibe. There are so many factors that can contribute to a vibe...

My total price with tax was $515. When I was looking, Scottsdale was a enough more expensive when you add center bearing, bearing supports, shipping, etc, etc. to push me to PTI. I decided to go with PTI also because of the servicable U joints, no foam lining on the shafts, and no more rubber flex coupling.

But, I understand the argument for OEM too. Best of luck.

EDIT - Price was $455 - I forgot that the $515 price included a $60 core charge...Tom
Modified by 91QAZ at 10:31 PM 4/1/2005

[Q45tech]

http://brickboard.com/FAQ/700-...nosis

RWD Volvo similiar

[Q451990]

As far as DIY replacement - it's not that big of a deal. You really don't even need to drop the exhaust. I've done it on five jack stands in a couple of hours. You just pull the four bolts at the differential flange, the center carrier bolts, and a couple of others (don't remember now) - and snake the shaft down between the rear exhaust tubes. I use an extra creeper to roll it out. One man job...

As far as the balancing issue. I just made a note of the ballance mark on the original shaft relative to the differential input flange, and put the new mark in basically the same position. No noticeable vibrations...

When you can get 100K+ out of an OEM driveshaft, I don't see much of a reason to go aftermarket... that's a pretty good track record.

Heath

[elwesso]

http://brickboard.com/FAQ/700-...nosis

RWD Volvo similiar

Good reading..... Sounds like if your frame bushings are bad that can cause things to be outta whack.....

Tom, when you replace your bushigns be sure to use the poly bushings or nismo rubber ones.....

When you can get 100K+ out of an OEM driveshaft, I don't see much of a reason to go aftermarket... that's a pretty good track record.

Heath

I dont want to beat a dead horse but remember its not the metal that fails.. The U joints, center bearing and the foam insulation is what causes the problems and this is what PTI's shafts eliminate... makes all that stuff easily serviceable...