What makes the rear wheels sit forward in their wells?

[jmortensen]

The 300ZXT axles are too long as well. I have a fix for this though: http://forums.hybridz.org/index.php/topic/102798-short-z31t-cv-shafts-group-buy/

I should have the Z31T adapters for 280Z stub shafts around the end of January if you would prefer to deal with me.

[BTF/PTM]

Jon, you should set up a group buy after both those shafts and the pending flange adapters are available. I'd surely sign up!

[Jetaway]

My Z (1972) developed over time two different wheelbases with the driver's side ending up an inch shorter than the passenger side. It took me a year, a lot of head-scratching, research, and measuring, before I got it doped out.

Hope I have that terminology correct here. The rear mounting bracket on one of the transverse links had loosened and was not in parallel with with the frame crossmember. It wasn't much off, hell I had looked at it several times before, but a close inspection did reveal that it indeed was off. Loosened up the differential carrier frame bolts and whacked it a few times with a small sledge. The bracket moved at most 1/10th of an inch to line up and that brought the wheel back an inch into parallel with the other wheel.

Chris

[jmortensen]

There will be a package deal. Anyone who bought shafts in the group buy will get the package deal price if they buy adapters. Just waiting on machinists at this point...

[BTF/PTM]

This is great input, thanks! I'd heard of the upper "dog legs" that extend down to hold the rear of the differential warping over time (which is another thing I'll check when the the car is apart), but not having to shift the suspension around with a hammer! Any chance you could snap a few pictures of specifically what was loosened and what you hit to move things around?

My Z (1972) developed over time two different wheelbases with the driver's side ending up an inch shorter than the passenger side. It took me a year, a lot of head-scratching, research, and measuring, before I got it doped out.

Hope I have that terminology correct here. The rear mounting bracket on one of the transverse links had loosened and was not in parallel with with the frame crossmember. It wasn't much off, hell I had looked at it several times before, but a close inspection did reveal that it indeed was off. Loosened up the differential carrier frame bolts and whacked it a few times with a small sledge. The bracket moved at most 1/10th of an inch to line up and that brought the wheel back an inch into parallel with the other wheel.

Chris

[Jetaway]

BTF/PTM,

I can't really take photos right now because I have the front end in the air and their just ain't that much room left under the backside. I am attaching a photo of the offending bracket. Note the slightly squarshed looking rubber bushing. Didn't realize the significance of it at the time, but this is what I eventually took a small sledge to. I loosened maybe ten to twelve nuts or bolts in all. Any and all of the bolts that attach the differential carrier to the body, including the indirect attachment through the "dog legs." Nuts and bolts attaching the differential to the carrier, I did _not_ loosen. One of the dog legs was bent, but only because it was forced out of position. Once I whacked the bracket into place, the dog leg straightened out and hung nice and perpendicular to the ground.

Chris

[BTF/PTM]

This is great stuff, thanks for the picture! It took me a couple days of staring at that picture and reading your posts before I fully understood it. Had to dig all the old four-bar linkage stuff from my college days out of the recesses of my brain. It does make sense, a tweek on a very small bracket at the inner end can translate to a large discrepency when placed across a 14-inch swing arm.

I'm guessing you didn't loosen the bolts much, maybe a half turn or so, just enough to maintain component contact and reduce friction enough to be able to push the parts around?

[Zed Head]

Since you're thinking about - these two mounting points are supposed to be somewhat self-adjusting when the weight of the car is on the suspension. The mounts are left loose, the car is settled on to the suspension and rolled around a bit to get everything in its proper position, then the eight bolts are torqued down. You can reach the bolts when the car is on the ground, if your exhaust pipe is not in the way. Might be worth some time to reach up under there, loosen them up and see if you can get things settled right. It won't hurt anything and you might get an easy adjustment.

[LeonV]

Since you're thinking about - these two mounting points are supposed to be somewhat self-adjusting when the weight of the car is on the suspension. The mounts are left loose, the car is settled on to the suspension and rolled around a bit to get everything in its proper position, then the eight bolts are torqued down. You can reach the bolts when the car is on the ground, if your exhaust pipe is not in the way. Might be worth some time to reach up under there, loosen them up and see if you can get things settled right. It won't hurt anything and you might get an easy adjustment.

Good point. This is one of the reasons why suspension fasteners must be torqued with the car fully laden. If someone torqued the suspension down with the wheels in the air, problems like this one can arise.

[jmortensen]

FWIW, moving that hanger is only going to affect toe. The fore aft is still going to be the same because the front of the control arm is captured by the front bushing which bolts to the frame via the front diff crossmember. The mustache bar holds the diff completely independently of the hangers.

[gnosez]

Before Jon had the great idea of making the correct length shafts I toasted a rebuilt 3:90 pinion in all of 50 miles after installing a set of aftermarket (autozone) 300zxt CVs in my 240 (with the MMS adaptors).

In this case the ones from autozone were two left (or rights) and of course one side was too long causing the CV to press into the side of the diff. Lots of gray and silver bits came drained out of the diff. I got a set of real 300zxt (both left and right sides but found that there was still the very real possibility that one side would bind on my very lowered car.

To solve this I went out and got a set of Dave's Arizona Z car RCAs and adjusted the angle of the inner tube to match the CV shaft lengths. This also gave me a more upright arm that was lacking in the stock setup once I lowered the car. A time consuming chore but in the end (no pun intended) it worked. The 240 now has over 10,000 miles, including some track time and not a spot of problems (or little metal bits in my diff).

Had Jon's shafts been available back then I would have gotten them as well for added insurance. Nice to see another solution from within the Z community.

[Jetaway]

FWIW, moving that hanger is only going to affect toe. The fore aft is still going to be the same because the front of the control arm is captured by the front bushing which bolts to the frame via the front diff crossmember. The mustache bar holds the diff completely independently of the hangers.

Sorry about the delay.

Actually, it did more than affect the toe. I had the car parallel to the ground a foot and a half in the air and dropped many a line for point-to-point measures. I can't pretend to tell you the mechanism, but every measure I took indicated that center of the rear hubs moved, bringing the right and left wheelbase much closer in length. Professional before and after thrust angle measures also showed a much closer alignment with the body.

Chris