Driveshaft question
Driveshaft question
When you buy a two-part Q45 driveshaft from the dealer, does it come in pieces, or already joined at the companion flange?
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greg_atlanta
- Posts: 1111
- Joined: Tue Jul 23, 2002 4:37 pm
- Car: 2008 G35 Journey Sedan, silver/black (no sunroof), 1992 Q45 (in a past life)
It's frustrating... I considered doing a custom shaft. Talked to a driveshaft shop in town which offered a one piece shaft installed for $300, but a year later they decided that didn't work and they would mimmick the factory shaft for around $500-600.
Decided to get the OEM shaft and it's better, but not $900 better. But I might need motor mounts replaced to make a better judgement... sometimes hard to distinguish one vibration from another.
If it's not bothering you I wouldn't bother replacing it. If you order from Scottsdale it'll still cost $75-100 just for shipping, I think.
Decided to get the OEM shaft and it's better, but not $900 better. But I might need motor mounts replaced to make a better judgement... sometimes hard to distinguish one vibration from another.
If it's not bothering you I wouldn't bother replacing it. If you order from Scottsdale it'll still cost $75-100 just for shipping, I think.
I have not had much time lately to take care of the drive shaft problem- however; I have located a precision drive line shop here in Phoenix (does not look like a precision shop to me...) willing to press out the bad u joints and replace them with a new one. He showed me the parts cataglog that have Q45 listed as on the cars for which that company makes the U joints. The cost for each joint replaced is $45 with $65 for drive shaft R&R - I am willing to gamble with $110 - just waiting to find some time on a Saturday to do this...
Scottsdale price was exceeding $700 after taxes and freight for me (as I am local in Phoenix...)
Scottsdale price was exceeding $700 after taxes and freight for me (as I am local in Phoenix...)
I may be going the aftermarket replacement too
I read about http://www.driveshaft.com They are 1/2 the cost for the shaft
Check it out
I read about http://www.driveshaft.com They are 1/2 the cost for the shaft
Check it out
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Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Good luck! We always have people trying to out guess factory engineers. We always have shops trying to get your money for their expertise in Ford trucks.
Every aftermarket we have installed for someone ended up getting replaced by a factory unit [we warned them] as they just didn't understand how low in vibration the Infiniti units is or can be when installed correctly.
Is twice to 3 times the vibration worth half the cost?
Owners keep resisting the fact that they wore out the unit and didn't save money to replace it.
Every aftermarket we have installed for someone ended up getting replaced by a factory unit [we warned them] as they just didn't understand how low in vibration the Infiniti units is or can be when installed correctly.
Is twice to 3 times the vibration worth half the cost?
Owners keep resisting the fact that they wore out the unit and didn't save money to replace it.
Dennis -- good point about balancing to 140 mph. My back-of-the-envelope calculation says the driveshaft would be turning close to 7500 rpm. Approximating from tires backwards ((~900 tire revs/mile * ~3.5 driveshaft revs/tire rev * 140mph)/(60 minutes/hr)) = 7350 driveshaft rpm.
firstq -- since you're sorta new to the party, the driveshaft is constructed of inner and outer sleeves, separated by an insulating material. Apparently as it deteriorates, this material can move and unbalance the shaft. I mention this because driveshaft vibration is not necessarily the u-joint. If you approach driveshaft vibration doing the cheapest, easiest thing first, then progressing to more expensive or involved solutions, that's a place to start. Could be the center support, too. I think Greg had trouble with that. Myself, instead of playing with pieces of it, I think I would replace the whole shaft, eliminating several possibilities and potential liabilities in one swipe.
greg -- I'm looking ahead in my vibration-abatement program. Wheels and tires in the next month, then we'll see where that puts us. transmission mount & all hangers, motor mounts, and driveshaft in that order if the vibrations persist. Triage -- it's all about triage.
The vibrations keep changing. As recently as September, there was a hard vibration spike at 60 mph. Now 60 is it smoothest speed. Something is changing pretty dramatically. Without Dennis' spectrum analyser, I'm left to guess at a few possibilities:
a) the driveshaft foam layer is really bad and keeps shifting b) the internal deterioration of the tires is going really fast c) the inevitable water in the tires (from inflation with wet air) moves around, or becomes vapor as the tires heat up (I have a water-separator for *my* compressor, but the previous owner used those 50-cent machines.) (Hmmm . . . changing the air in the tires used to be a joke. Maybe heating them up, venting, and refilling with drier air would help . . . that's an idea.)d) the wheels have thrown more balancing weightse) various driveline imbalances are just going in and out of phase f) thermally induced changes in exhaust-system dimensions changes exhaust-system harmonicsg) thermally induces changes in exhaust hanger rubber, dittoh) the locking pliers I "installed" on the exhaust-system harmonic damper really are spoiling the 60 mph vibration.
The sad old wheels and rubber I've got came with the car. They're not even worth a rebalance when replacement is so close.
firstq -- since you're sorta new to the party, the driveshaft is constructed of inner and outer sleeves, separated by an insulating material. Apparently as it deteriorates, this material can move and unbalance the shaft. I mention this because driveshaft vibration is not necessarily the u-joint. If you approach driveshaft vibration doing the cheapest, easiest thing first, then progressing to more expensive or involved solutions, that's a place to start. Could be the center support, too. I think Greg had trouble with that. Myself, instead of playing with pieces of it, I think I would replace the whole shaft, eliminating several possibilities and potential liabilities in one swipe.
greg -- I'm looking ahead in my vibration-abatement program. Wheels and tires in the next month, then we'll see where that puts us. transmission mount & all hangers, motor mounts, and driveshaft in that order if the vibrations persist. Triage -- it's all about triage.
The vibrations keep changing. As recently as September, there was a hard vibration spike at 60 mph. Now 60 is it smoothest speed. Something is changing pretty dramatically. Without Dennis' spectrum analyser, I'm left to guess at a few possibilities:
a) the driveshaft foam layer is really bad and keeps shifting b) the internal deterioration of the tires is going really fast c) the inevitable water in the tires (from inflation with wet air) moves around, or becomes vapor as the tires heat up (I have a water-separator for *my* compressor, but the previous owner used those 50-cent machines.) (Hmmm . . . changing the air in the tires used to be a joke. Maybe heating them up, venting, and refilling with drier air would help . . . that's an idea.)d) the wheels have thrown more balancing weightse) various driveline imbalances are just going in and out of phase f) thermally induced changes in exhaust-system dimensions changes exhaust-system harmonicsg) thermally induces changes in exhaust hanger rubber, dittoh) the locking pliers I "installed" on the exhaust-system harmonic damper really are spoiling the 60 mph vibration.
The sad old wheels and rubber I've got came with the car. They're not even worth a rebalance when replacement is so close.
Todd - my understanding is that the bad U joints are fairly easy to identify - they just do not move smoothly, the movement is jerky - that is what the fron U joint is doing on my drive shaft. So I know that it is bad and have to be replaced, before I look for other problems, what do you think?
The shop claims they can balance the whole shaft (goot to know with what rpm they should...) - as you are saying there may be other issues (carrier bearings, insulating material etc).
On my Q, I get a pretty strong & consistent vibration at 30MPH and I have changed 3 sets of tires in as many months (with other stuff already taken care of), I am pretty sure the vibration is most likely related to the drive shaft, will find out sooner or later.
Only if I could desensitize my behind so that it would not bother me every second of an otherwise confortable drive...arghhhhh
The shop claims they can balance the whole shaft (goot to know with what rpm they should...) - as you are saying there may be other issues (carrier bearings, insulating material etc).
On my Q, I get a pretty strong & consistent vibration at 30MPH and I have changed 3 sets of tires in as many months (with other stuff already taken care of), I am pretty sure the vibration is most likely related to the drive shaft, will find out sooner or later.
Only if I could desensitize my behind so that it would not bother me every second of an otherwise confortable drive...arghhhhh
Hey Guys...I have been reading your posts on the Q45 driveshaft.I have info on a completely servicable aftermarket alternative that is available for around $400 (give or take). Premium Spicer racing joints are used on the shaft and it is insulated similar to the factory shaft (w/o the inconsistencies of foam). This is my first endeavor into the Q45 driveshaft situation. Please either reply to my post with any questions or interests, or of course you can e-mail me as well.....