rear end damage, fred, joe, whoever can help... w/in!!

[raroZ28]

Here is the damage I posted about earlier. TA is destroyed. Weird now too, that the driveshaft, when all the way in the trans, will not reach the rear end. I have to pull it out about 1" outta the tranny. It will still stay in there, but it doesn't line up with the black marks that are on the shaft, that tells me where it used to be. That's what's making the clicking noise I think, because I can hear it beneath the center console when I let the car roll.




Notice too how the wheels are not centered in the wells. I have an adjustable panhard bar, I am thinking maybe it came loose? I will adjust it in a bit to see if that helps.

I have a couple of cool guys at cz28 that are willing to give me their old stock TA's, but I don't know if that's enough to fix this problem.

Insight?? I don't know anything about rear ends. I just know this one is cock eyed and jacked up.

[Joe 1320]

The panhard rod centers the rear in the chassis. If the wheels are pushed backwards, that indicates a problem with the lower control arms and/or torque arm. You could have squashed the control arm bushings....... it's going to be difficult until you get a torque arm in there.

[Injuneer]

When you had the problem initially, you said there were parts rattling around in the rea end. Did you every verify what the condition of the differential was?

My reaction to your original post was that the gears broke, jammed the rear. When that happened, the wheels stopped, the pinion was forced down, and it ripped the torque arm off the front of the diff housing. That would also explain why the rear axle has been displaced backwards from where its supposed to be.

All that is speculation though, on the assumption you jammed the gears. Did you verify the extent of damage to the differential?

The panhard rod doesn't control the front-to-back spacing of the wheels in the wheel openings. That is controlled by the LCA's. You need to look at the LCA's, and both the front (body) end mounts and the rear (axle) end mounts to see if something is bent or broken.

When you insert the drive shaft all the way into the trans until it stops, its in too far. It should be backed out at least 1/2" from the bottoming out point, to provide clearance for the changes in DS length as the rear suspension moves through its full range. 1" is too much for a relatively stock setup, but might be OK for a really high HP application. Again, the rear axle has moved backwards, and the LCA's and LCA mountnig points are "the usual suspects" in that case.

[raroZ28]

Thanks for the replies.

The rear end gear is fine. I pulled the cover and the gears are perfect, the wheels will spin fine, etc...

The lower control arms and mounts appear to be fine. I haven't pulled them to check the bushings though. They're the BMR LCA's, only about 8 months old. Where it bolts isn't bent or stretched. I just don't know how I'm going to get the torque arm on there. I will have to somehow pull the rear end forward to get the torque arm to bolt on.

Could I use a come along to get the TA on there? Bolt it to the front frame, wrap it around the rear, and pull it forward? Will I have to loosen the LCA's to do this??

I'm hoping this was JUST the TA and nothing else.

[Joe 1320]

You'll have to jack up the rear of the car, put it on stands that support the chassis rails. Then use a jack to raise and manouver the rear end assembly. A prybar will help in rotating the assembly in order to get the arm and the bolts to line up. It's not hard. Probably the biggest pain is getting the front of the arm into the front torque arm mount. Most times the transmission crossmember must be dropped in order for the torque arm mount bolts to be removed. You can loosen them, but you won't be able to remove the bolts without dropping the rear of the trans slightly.

[raroZ28]

Thank you for the responses Joe.

Would you say it's a better idea to put the front of the torque arm in first? Where it mounts to the tranny? Then mount it on the rear end?

Couple guys on CZ28 were gonna gimme a free one, a guy that lives closer is gonna sell me his for 10 bucks. Waiting on him to get me his # and I can go pick it up. I love the internet. Hopefully that's all I need to fix!

[Injuneer]

If the pinion shaft is rotated up the way its sitting now, that explains why the wheels are not centered. As the pinion shaft rotates up, the axle pivots around the end of the LCA and the centerline of the rear moves backwards. When you get the weight off it, and put a floor jack under the pumpkin, you will be able to rotates the pinion shaft down so it is level and the TA will fit right over it. Having it already in the front bushing will help. You just need to make sure you have room to get the bolts in from the top.

I did a complete 10-bolt to 12-bolt swap with the car on jackstands and the rear axle assembly resting on a floor jack. I used the floor jack like a dolly to move the old rear out and the new rear in. I was working totally alone, so its not a matter of using any appreciable force. I was able to get all the parts lined up and put the bolts in, although it was with an aftermarket TA. At one point I did lose control of the axle, and it rotated around the LCA's and the pinion whacked me up side of the head..... damn that hurt!!!

[Joe 1320]

At one point I did lose control of the axle, and it rotated around the LCA's and the pinion whacked me up side of the head..... damn that hurt!!!

Thanks Fred. I though I was the only one who experiences those kind of results.

[raroZ28]

You guys are very supportive and helpful. I really appreciate it you guys.

The new torque arm is in, and the rattling sound is gone. Car feels very tight now too. BUT, there is a little chatter, like something vibrates, then bounces off the bottom of the car, then it stops. Very tiny. I remember another member posting about a similar problem after he had his clutch installed. The shop forgot to bolt something on the TA? I am thinking maybe my torque arm mount is shot from the damage. The car drives, and when I get on it, it seems all right. I didn't get too crazy with it though. It's very driveable now. It just has that bouncy "thuck thuck thuck......" Then it stops.

[Joe 1320]

Could be a broken trans mount. Also, what pinion angle did you set?

[raroZ28]

How do you set the pinion angle?

[Joe 1320]

The pinion angle is adjusted using the threaded ends that connect to the differential end of the torque arm. The kit should have come with a magnetic angle finder which is used for the measurement. Ideally you want about -2º or 2º down for street use.

[raroZ28]

I put in a stock torque arm, so I didn't think I had to do that. You're talking about the dial that comes on like the SPOHN or BMR?? I remember my manual saying something about the pinion angle, but they just said to make sure the put the shaft in the same way you took it off, which is what I did, so it should keep the angle the same.

Whatever is vibrating is on the pass. side. It vibrates whenever the car is idling. Gets less noticeable as I drive more. Worst at cold startup. I have no idea what it could be. I need to get the car on a lift. I'm thinking it must be the trans mount or torque arm mount.... Either way it's annoying. Car drives fine, I can gun it and everything, nothing out of the ordinary, but it's just making that creaking sound, and vibrating.

[Joe 1320]

I put in a stock torque arm, so I didn't think I had to do that. .

Ahh.... my mistake, I thought you put in an adjustable one.

[Jeff_in_Atl]

Is the right rear tire centered up in the tire well now?