wheel bearings, brakes, driveshaft.....DRIVESHAFT!!! ACPT Carbon Fiber(a little long)

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HeavyDuty
Posts: 1281
Joined: Tue Sep 23, 2003 4:51 pm
Car: 1995 Infiniti Q45
95 Nissan 240SX S14
96 Nissan D21
06 Nissan 350Z Z33

Post

Knowing I'm taking a trek to Grandma's house on Friday (my children's Grandmother, that is) I decided to do a little maintenance on the Q.

New OEM pads f&r, (actually just fronts, the rears were oem & new per the previous owner) and a good time to install my wheel bearings, since Orlando Infiniti & another so-called tech advised the previous owner the bearing noise in my drivetrain was the rear wheel bearings.

Ordered them from the local dealer, he casually mentioned there were two different prices. That's funny, I thought, as I dissasembled the left rear brake assy, axle, etc. the new ones don't *look* different.............wait a minute...... what's the p/n on the box????? (Good thing I had my Handy-Dandy p/n disc) Same part number for both....ARRRGGGGHHH!!!

He sent me two lefts. So, rather than reassemble everything, while the driver's side axle was out, I started the car and used the brake to hold the right rear wheel still while listening to the driveshaft & rear diff freewheel. THAT"S THE NOISE! It wasn't the wheel bearings at all, they're fine.

It was the driveshaft (propeller shaft, whatever) center bearing. Which I see (again, per the disc) is not serviceable *at all*.

Great. :mad:

So, now it comes to pass I need a driveshaft. Better to find out now than spend 5 hrs replacing 2 $150 bearings for nothing. But, I understand the shafts are anywhere from $500-$900 depending on where I looked online today.

Inclusive of where I searched via Google, I found an article about the ACPT carbon fiber driveshaft. http://www.acpt.com/driveshaft/driveshafts.html

Does anyone know how much they are? Total overkill for my current combo, but if a new one is $900 & an ACPT is $1,000-$1,200, I might be tempted after reading their site. Someone on this site has one & mentioned it in a post.

5% hp gain at the wheels? Hmmmmmmm, not exactly a bang for the buck, but it's something & I need one anyway.


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

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Bad driveshafts tend to wear out diff pinion input bearings and transmission tail shaft seals and channels.

Never had good luck with carbon fiber or other one piece drive shafts.............after lots of work the new shafts feel just as bad as the old worn out shafts.

5% gain humbug!.........do the math.........11-12 HP maybe half that and the vibration.

HeavyDuty
Posts: 1281
Joined: Tue Sep 23, 2003 4:51 pm
Car: 1995 Infiniti Q45
95 Nissan 240SX S14
96 Nissan D21
06 Nissan 350Z Z33

Post

Yup, I suspected a little noise from the pinion bearing too. The transmission is newly rebuilt, so I want to take care of his ASAP. If it's time to do the pinion bearing, 4.08's & a complete overhaul is the order of the day.

I know 5% is a so-so gain for a big expense if the part being replaced is good, but if it's needed anyway, it becomes worthy of consideration, imho.

Were the cf units you used the ACPT ones?

Thanks for the response.


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