300ZXT CV Issue

[gnosez]

So, who has swapped out their half-shafts and gone over to CVs? Have you experienced problems after doing so?

 

I switched over to 300ZXT CVs using M-MSports companion flange adapter (for 280 stub axles) for my R200 (3:90 quaife) diff.

 

The first set of CVs were aftermarket (AutoZone) and they destroyed the pinion gear due to the fact that one side (driver) had a longer shaft than was required.

 

On lowered 240Z this extra 3/8 - 1/2-inch was all it took to push the ring gear into the pinion and wear it down in under 200 miles of highway driving.

 

I took my Z out today for the first time in 4 months (the roads here in New England still have salt on them - #@!*&^%) and I found myself paying more attention to potential diff noises and less on enjoying a ride in a real car.

 

Am I the only one who has had this problem?

[JMortensen]

There have been people who have found that the CV shaft was too long, and this resulted in the CV breaking. I think this is the first I've heard of it causing problems with the pinion gear. What you're saying about the shaft pushing on the side of the diff might be true, but I'd expect the carrier bearings to be able to handle a whole lot of load and I'm a bit surprised that you found that it cause the pinion's destruction. Maybe your carrier bearing (or maybe even the diff case) was weak for some reason and it allowed the ring gear to move in relation to the pinion? Pure speculation...

 

One solution would be making a shorter CV shaft for the driver's side, I think mayolives and some others have done this. Extending the control arm length would also work. This has been talked about but I'm not sure if it has been done specifically for this purpose yet.

 

EDIT--If you're using the RT diff mount you might also be able to move the diff to the passenger's side a bit by redrilling the holes in the mustache bar and the diff mount.

[rudypoochris]

Instructions on the modern-motorsports webpage let you know that you need to shorten the shaft:

 

* 300ZXT 4 bolt outerflange CV shafts (not the 6 bolt type) require the end cap removed, and inner CV race reversed, this effectively shortens each CV shaft 3/8" and results in correct rear geometry for your Z. This modification can be done with typical tools and we can supply guiding pictures to help (easily done in 1/2 hour). They work with stock rear control arms, if you've shortened yours or any similar effect be sure to check for adequate travel without binding in compression.

It was sort of a pain in the butt, but it wasn't that bad. Wouldn't take very long at all if I had to do it again. Instructions are attached - Enjoy.

Z31 CV SHAFT SHORTENING STEP BY STEP.pdf

[gnosez]

I've flipped (as per MMS instructions) the aftermarket set, the set I borrowed from Roostmonkey and the set I bought for myself.

 

Been there and done that.......

[SATAN]

In order to wear down the pinion or the ring gear inside of 200 miles, you differential should have been making horrible noises! Was there something else going on that you just did not hear it or did you not know that the sound was abnormal?

 

That and I'm with Jmortensen, your ring gear should never have actually moved to wear out the pinion. Did you move shims around inside or something that would cause this? Bearings were fried too right?

[gnosez]

The car started making noise about 10 miles from the race track. I didn't use the car that day and on the ride home it got progressively worst.

 

After we cracked open the diff we found that the bearings were gone, the bottom of the diff was filled with fine gray sludge and the pinion was bright (the ring gear was fine).

 

So, yes there was noise, a lot of ugly noise but at that point I was more interested in getting home than ruining my diff.

 

I agree that this seems to be more of a mis-alignment issue but the only thing that was changed in my rear driveline set-up was the addition of the MMS flanges and the CVs.

 

Are the stub axles spacer sleeves different sizes for 240 vs 280? If so a longer sleeve would push the companion flange out that much further.

 

At this point I'm thinking of going back to half-shafts.

[getZ]

I have done the swap and don't think they fit correctly. There was sombody here who also lost a diff. I won't drive my car more than a couple of miles until this problem is resolved. The other guy who said he had problems went with a Quaiffe.

 

My axles are flipped and I still think they were about an inch to long. To me the first sign of trouble was when it was difficult to swing the shock tower back into place with the CV mounted on the pumpkin. You should be able to disengage the CV with the shock tower already bolted up. DO NOT FORCE the assembly back together.

 

Personaly, I would not recommend my current setup, 72 240z, 88 r200, aftermarket LSD (I forgot the brand, it was from Reider's), 300zxt cv's, 240z spacers and MM stub axles. Currently I am looking to get a custom CV made up and be done with this issue. It makes me uneasy seeing the CV boot all bunched up.

[JMortensen]

I have done the swap and don't think they fit correctly. There was sombody here who also lost a diff. I won't drive my car more than a couple of miles until this problem is resolved. The other guy who said he had problems went with a Quaiffe.

The LSD type has nothing to do with the problem being discussed here. If he went with an R180 and a Quaife that would be a solution, but then he wouldn't be using CV joints, unless he got something made for a 180.

Personaly, I would not recommend my current setup, 72 240z, 88 r200, aftermarket LSD (I forgot the brand, it was from Reider's), 300zxt cv's, 240z spacers and MM stub axles. Currently I am looking to get a custom CV made up and be done with this issue. It makes me uneasy seeing the CV boot all bunched up.

I think mayolives or mark or one of those NC guys had a line on a shop that would make the center shaft for the CV's shorter. That's the quickest easiest way out of this predicament.

[mark]

Jon is right I used http://www.driveshaftshop.com/ in Salisbury NC. They made a set for 550. They will also reassemble your axels. I would be interested to know the lengths of the shafts you have. The pair I had made were shorter than the ones Tom had made.

 

The axels I had that were too long would have been short enough for Tom to use. Tom is using the 300 set up like you have, I have the 280 ZX set up.

 

I'm not sure of the difference in the shaft diameter and spline count between the two shafts.

[getZ]

The LSD type has nothing to do with the problem being discussed here. If he went with an R180 and a Quaife that would be a solution, but then he wouldn't be using CV joints, unless he got something made for a 180..

 

My thinking about diff was the width may be slightly different, not much maybe a half to quarter inch different, or the axles may slip in further, but I'm just guessing at this point.

 

BTW, there was another thread with actual lengths of the 300zxt cv's, it had pictures as well. I guess I'll go back and remeasure everything out again. Thanks for the link to the driveshaftshop.

[mark]

If you completely take your axels apart, measure the length and post it. I would be interested to see how close the lengths you have were to Tom's.

 

If the 280 and 300 shafts are the same I may have something you could use.

 

Have you discussed this with Ross? I think it is interesting that this set up has cause similar problems on 2 cars.

[gnosez]

If you notice on MMS' CV page they mention that lowered Z might have a binding problem. I had discussed this with JohnC and as per his suggestion, I ran the struts through a complete range of motion (w/springs removed) and they didn't bind. A severe squat (bump or launch) could make the rear dip quite a bit.

 

I intend on slowly grinding down the shaft end (1/4) once I get back from overseas. That I hope will resolve the issue once and for all.

 

Oh, I did pick up another 3:90 ring set just in case.

[JMortensen]

If you notice on MMS' CV page they mention that lowered Z might have a binding problem. I had discussed this with JohnC and as per his suggestion, I ran the struts through a complete range of motion (w/springs removed) and they didn't bind. A severe squat (bump or launch) could make the rear dip quite a bit.

 

I intend on slowly grinding down the shaft end (1/4) once I get back from overseas. That I hope will resolve the issue once and for all.

 

Oh, I did pick up another 3:90 ring set just in case.

How did you test for bind? Did you move the suspension by hand or did you use a jack? You can feel a lot more moving it by hand.

 

My impression is that shortening the end of the CV where it plugs into the diff or the end of the shaft that connects the two CVs won't do any good. You need the splined areas where the CVs connect to the shaft to be closer together. The CV has a telescoping function built in, but it's running out of room. The solution is to shorten the shaft (not the end, the distance between the splined areas) so that the CV can do it's job properly.

[Kash]

I have had the same issue upon installing my 300zxt CV adapters from MM...almost impossible to turn the wheels after putting everything back together (and I did flip the ends around)...had to drop the driver's side lower control arm and us a floor jack to get it back into place in order to get the axle in.

 

I current have everything apart for my LSD swap and I have been seriously thinking about grinding or cutting off that extra 1/4 inch up to the clip on both ends. GNOSEZ, let me know how it turns out if you go at it before I do.

 

I find it hard to believe that MM did not see this as a problem when they created the adapter, even after flipping the ends; this set-up is about an inch too long on each side. It would be nice if they also offered a new shorter shaft for these adapters, at a discounted price:)

[Guest 1Fast240Z]

Are the adapters from MM causing the issues with binding, or are they the z31 cv's themselves?

 

I'm getting ready to swap in a 4.11 R200 into my 240Z, and I want to make sure I have all the right parts so as not to cause any problems.

[Modern Motorsports Ltd]

>>I'll insert some comments below. Maybe we've received this question from you and did address but doesn't seem any direct match?

 

So, who has swapped out their half-shafts and gone over to CVs?

 

>>A few hundred with a hundred plus on the Z31's since Jan 2003. Before us they were proven out with a few dedicated track racers in Ontario with identical geometry.

 

Have you experienced problems after doing so?

>>Typical item is shortening your outer swaybar end link with a short high grade bolt. Always suggest verifying your suspension travel that your shafts have appropriate travel and don't see full compression in your travel range for use.

 

>>If you've narrowed your rear or dropped it a lot you may get into bind and that would show up in typical test of your suspension. This is NOT to see if it's happy at full droop as that's not a normal condition unless you're a desert rally racer/jumper.

 

I switched over to 300ZXT CVs using M-MSports companion flange adapter (for 280 stub axles) for my R200 (3:90 quaife) diff.

 

The first set of CVs were aftermarket (AutoZone) and they destroyed the pinion gear due to the fact that one side (driver) had a longer shaft than was required.

 

>>aftermarket often seems to screw up these rebuilds as they have several same spline but slightly varied length donor male sections. We quit dealing with aftermarket hiccuped axles (rebuilds) after one with a errant middle section. I'd only run original OEMs/at most update boots. The CV's are very tolerant and don't seem to justify any rebuild. 9 second 1/4's Ben cut on his used Z31 set. We should find that specific length data to help all confirm they've got a perfect length set for their install.

 

On lowered 240Z this extra 3/8 - 1/2-inch was all it took to push the ring gear into the pinion and wear it down in under 200 miles of highway driving.

 

>>did the axle have travel thru the suspensions functional range?

 

I took my Z out today for the first time in 4 months (the roads here in New England still have salt on them - #@!*&^%) and I found myself paying more attention to potential diff noises and less on enjoying a ride in a real car.

 

>>That's NO fun at all, I hate suspect noise! Have you confirmed axles are happy thru your intended suspension range? ie. still some compression available at what you'd believe to be full droop in function? (or full compression/ie. very lowered car). Did your quaife have the circlips/Clips installed to retain the CV inputs? Quaife missed those on a small shipment last year, one of our customers was affected and installed the clips on his own.

 

Am I the only one who has had this problem?

 

>>Tom Barnett encountered it with a very lowered car with axles pointing up and outward (vs. horizontal or out and down etc as John typically recommends). Tom informed us he had a custom set being made 7/8" shorter to keep his axles happy and we've not heard further.

 

We could easily make custom center bars for these but have not had the request (easily done by our manufacturer) or knowledge of issues in addition to Toms. If a few sets can be justified then our usual $340 for a pair of custom bars. (no question it's a tight install but it's worked great for many combos' for some time, we're open to change always - just looking to fully undestand and ensure any change is the appropriate one) Just curious what are you guys typically paying for a set of used CV axles these days?

 

kash, hopefully your query's answered in our response above. We ONLY proceed on what's either been proven (by ourselves or others) and/or is very well founded in sound engineering practise with our products and combinations. The other factors will always continue to change and to those we respond as best we can with our usual support and continued design over the last 7 yrs. It's the continued support of those with the same strong progressive attitudes that we so greatly appreciated in marching onward with new offerings.

 

Some setup guru's would not drop their cars 2.5/3" etc, some do so introduces new parameters both for angularity of the CV's and shaft travel as their geometries revised. Assuming the CV's are OK with their new angularity (often ignored) range, then the shortened shafts should put them back in their happy zone.

 

Any want some shorter centers because they're narrowing their rear or dropping their car notably (less than 1% noted any issue to date) please drop us a line. We'll gladly get you a set.

[NZeder]

We found on mates 240z that flipping the CV cage was not enough we used 2 sets of axles using 2 short axles. On the shorter side of the axles he shortened the axle before the C-Clip and as he is using the 280zx type lock nut not the penn type nut he also shortened the stub axles this gave enough clearance to get the axles in without binding throughout the travel. The short axles on the long side with the correct diff input resulted in no cage flip and no clearance issues. So in the end we had 2 custom axles for the short side made, one for my zed and the other for my mate's 240z.

 

Not sure if it makes a difference but my mates 240z is a early body shell ie originally had the diff forward and the hand throttle/cable next to the choke cable. How many others with the lenght/bind issue are these early shells? As the suspension is out of my later 260z I can't comment if I need the custom axles but given I have it now I will be using it anyway (again this custom axles is only for the short side and we are using the normal short axles on the long side with the correct ends) The custom axles is 10mm shorter if I recall correctly.

[JMortensen]

Some setup guru's would not drop their cars 2.5/3" etc, some do so introduces new parameters both for angularity of the CV's and shaft travel as their geometries revised. Assuming the CV's are OK with their new angularity (often ignored) range, then the shortened shafts should put them back in their happy zone.

 

Any want some shorter centers because they're narrowing their rear or dropping their car notably (less than 1% noted any issue to date) please drop us a line. We'll gladly get you a set.

There are good reasons to lower a Z more than 2.5-3 inches (see my sig). There are negative effects to doing so with stockish suspension, but it can be done in a beneficial way if the time and effort is utilized to do it right.

 

I think that with the emergence of larger and larger diameter wheels your percentage of problems with shaft length is likely to be more than 1% looking into the future, and this will be a good item for you to have in your product line. Big wheel guys have to lower the car further in order to get the look that they're after, and I don't see that trend changing any time soon.

 

Not sure if it makes a difference but my mates 240z is a early body shell ie originally had the diff forward and the hand throttle/cable next to the choke cable. How many others with the lenght/bind issue are these early shells? As the suspension is out of my later 260z I can't comment if I need the custom axles but given I have it now I will be using it anyway (again this custom axles is only for the short side and we are using the normal short axles on the long side with the correct ends) The custom axles is 10mm shorter if I recall correctly.

Having the diff located forward should increase the axle length and help alleviate this issue, but usually when people install an R200 they use the 280Z mustache bar which moves the diff back.

 

If I were doing a custom axle I'd probably go shorter than just 10mm less than stock, because the CV has probably closer to 2" of travel in it. Ideally it would be in the middle of its travel at ride height (assuming that leaves enough space at full droop and full compression). I think the thing to do is measure the distance from the diff to the companion flange at droop, ride height, and compression on a couple different cars and try to figure out if there is a "universal" size that works.

[getZ]

If I were doing a custom axle I'd probably go shorter than just 10mm less than stock, because the CV has probably closer to 2" of travel in it. Ideally it would be in the middle of its travel at ride height (assuming that leaves enough space at full droop and full compression). I think the thing to do is measure the distance from the diff to the companion flange at droop, ride height, and compression on a couple different cars and try to figure out if there is a "universal" size that works.

 

I think you are right, 10 mm might be to little. It probably needs to be about and inch shorter. On my car, I think the CV only moves about a quarter of an inch though the suspensions range. Idealy I would rather just have the shafts shortened, but I don't think it is possible because the diameter of the axle decreases where the spline needs to be recut.

 

BTW - I found this in a previous thread, for whatever reason the turbo shafts had only about 1.5 inches of movement

 

http://forums.hybridz.org/showthread.php?t=125503&highlight=300zxt+cv

 

We have a local CV joint shop here in town that may have some other ideas. The guys are good enough to tell you what type of car they came out of just by looking at them.

[NZeder]

Having the diff located forward should increase the axle length and help alleviate this issue, but usually when people install an R200 they use the 280Z mustache bar which moves the diff back.

Yep have a R200 in the rear now with the 260z (we didn't get the S30 280z locally steering wheel is on the other side) mustache bar so what I meant is that the car was originally a forward mount R180 however it is now changed/corrected with the R200 fitted too. I guess I was trying to see if all the other cars with the shaft length issue are all early shells that originally has the forward mounted diff (ie upgraded to the R200 with correct mustache bar and CV shafts)

 

I managed to find a stock Nissan CV shaft that is shorter than the 300zxt shaft - I will have to go out to the shed and find it and measure it again. This shaft has the same spline count/size as the 300zxt shaft just shorter, I think at the time I thought it was too short but I might have to revisit the maths again.

 

Again I will update shortly - later today my time.