Installing Caltracs. Can I just install the rear on top of the spring using the guide nipple and then install the bottom plate using 1/2 u-bolts? If I install the isolator pads either on top or bottom I'm afraid of the axle moving due to the locator holes not seating all the way. Can I JUST LEAVE THEM OUT?

Thanks.

unless you like excessive road noise i would put them in.
When I installed my moser rear with slide a link i had same dilema.
but I lubed the pins and pads and once I got the U bolts bolted down the pins squeezed in nice and tight.

You don't end up with more road noise in my opinion , i removed the rubber pads and made mine out of 6061 aluminum , i milled them into a 2 degree wedge so my pinion angle was correct . I'm also using a moser rearend .
Mark.

Well theres another problem. My car is lowered 1 1/2" in the rear with the hotchkis springs. If you look at the stock perches they pretty much touch the axle tube. The ones I have on the new 9" are universal ones and mount around 1/2" above the axle. So when installed the car would be 1/2 lower now. I can deal with that. If I install the pad I will be 3/4" lower then. Does it make any sense to install the pad below the axle?

I did not install the pads on mine, either. Like Mark (tho not as fancy as Mark) I used a small alluminum block to take up any extra space in the perch. I do not notice any extra harshness or road noise.

The only place that rubber and rear ends mix well is in San Farncisco. I would bolt them solid like a Mopar.

If I install the isolator pads either on top or bottom I'm afraid of the axle moving due to the locator holes not seating all the way.
Thanks.
This actually happened to me. The sleeve in the pad did not slide over the pin and caused a bad vibration because one side was closer toward the front than the other and i searched for this vibration for years. I just took out the sleeve but left in the pad.

If you have much HP, the axle can easily slip, the pads are not helping at all. I hate pads on any car that has much HP!
If you have non-factory springs, you need to check pinion angle, it's probably off.

If you have much HP, the axle can easily slip, the pads are not helping at all. I hate pads on any car that has much HP!
If you have non-factory springs, you need to check pinion angle, it's probably off.

I have Hotchkis lowering springs. What should the pinion angle be?

If you have much HP, the axle can easily slip, the pads are not helping at all. I hate pads on any car that has much HP!
If you have non-factory springs, you need to check pinion angle, it's probably off.


I did the TVS kit ,used the Iso. Pads and tightened the u bolts til the centering bolt nut protruded through the lower shock plate (used my mono ones)I am running my drag motor 500+ hp ,so how could the rear move if nut is through Lower shock plate to lock all in, wouldn't it be the same as my Mono stock setup with Traction bars??(and the centering pin in the hole in the Traction bars) With the same HP I never had a problem with Rear moving ??/ I do not know what my pinion angle is or s/b ????,It was a nice day yester so went for a drive got her on the freeway to 60 mph smooth as silk no vibration …that doesn't mean my P angle is correct maybe close ….I am kinda lost with David's answer…how could it move and what should pinion angle be??????...Thanks Jerome and Happy Motoring :)here is a pic of the left side shock plate and Isolator
http://i217.photobucket.com/albums/cc96/tamjss/GirlsHomingDance2007Camaropicsfp-6.jpg
http://i217.photobucket.com/albums/cc96/tamjss/68Camaro020.jpg

well this is the answer i got for a 10 bolt mono on my 67:

Chad:



Our leaf spring is designed off of a mono leaf car so it mounts no problem. The spring kit comes with four spring isolators that are mounted on the top and bottom. Just use the top isolator and do not use the lower isolator. You will have to drill out existing holes for our larger u-bolts. Other than that, you will be good.



For more accurate service, please include this e-mail with your reply.




Thank you,

Drew O.

Sr. Sales/Customer Service

Hotchkis Sport Suspension

well this is the answer i got for a 10 bolt mono on my 67:

Chad:



Our leaf spring is designed off of a mono leaf car so it mounts no problem. The spring kit comes with four spring isolators that are mounted on the top and bottom. Just use the top isolator and do not use the lower isolator. You will have to drill out existing holes for our larger u-bolts. Other than that, you will be good.



For more accurate service, please include this e-mail with your reply.




Thank you,

Drew O.

Sr. Sales/Customer Service

Hotchkis Sport Suspension

Yes I have talked to Drew a few times when I was installing my Kit ,I will call him to see what he suggests for Pinion angle..and verify lower iso. pad

I did call Drew ,and I told him about the talk on the T/C site about the lower iso. pads and he said to take them out lower only so I will be fishing them out,I asked about the Pinion angle he said the kit will not change pinion angle and not to worry 1.5 in drop is not enough to change the angle ...Happy Motoring

I did call Drew ,and I told him about the talk on the T/C site about the lower iso. pads and he said to take them out lower only so I will be fishing them out,I asked about the Pinion angle he said the kit will not change pinion angle and not to worry 1.5 in drop is not enough to change the angle ...Happy Motoring
The problem with most first gens is that the angle was never correct to begin with. To answer your question, check the angle of your transmission. That's the angle you should have for your differential pinion. Trany down, pinion up. Shoot for no more than 1 to 1.5° difference. Check these guys for more; http://www.iedls.com/measure.html

I have 6 leafs in my 68 and there wasn't room for the bottom pad so I have just the top and the springg bolt goes into the bottom shock-traction bar plate hole real tight, I also used two 1/2" U-bolts on each side. can't see it going any where.

The problem with most first gens is that the angle was never correct to begin with. To answer your question, check the angle of your transmission. That's the angle you should have for your differential pinion. Trany down, pinion up. Shoot for no more than 1 to 1.5° difference. Check these guys for more; http://www.iedls.com/measure.html


Thanks Fred ,first I am going to loosen all and fish out (sounds easy right)the lower iso.pads and then while I got her up and supported check the Trans angle and then see the pinion...I am sure I am close as no viberation exists(and as much as I drive or will be driving during the summer 3 months at the most 3 thousand miles U joints will last years ...Happy motoring

My 67 camaro came with mono leaf springs, the axle slipped forward on the left side.

Our second gen uses multi leaf springs with Hotchkis multi leafs. One thing I noticed on the chassis dyno was the axle rocked on the leafs when power was applied. I also saw this in the staging lanes at the autocross whenever the car was moved, I could see the brake caliper rotating with the housing. We had pads on the bottom and top of the leaf pack, with two 4 deg spring shims on top of the leaf to get the pinion angle correct. The spring shims were on top of the leaf, but they cut into the top pad, and the thickness of the shims prevented the leaf center bolt from engaging at the top. The only thing holding the rear axle was the lower nut, and it barely caught the edge of the lower hole. Looking up into the hole I could see it slipping past it.
David

You can see in this photo, the bolt head does not stick down past the poly pad. It may be hanging on by a thread, but not enough to stay. With two angle shims on top, the top end of the bolt does not protrude beyond the shims, so this photo shows all we had holding it at the bottom. The poly "cap" has allready sheared off, and the nut is slipping past the hole.
http://i117.photobucket.com/albums/o71/davidpozzi/Other/lower_bolt_offset2.jpg
http://i117.photobucket.com/albums/o71/davidpozzi/Other/ring_pad.jpg

The only place that rubber and rear ends mix well is in San Farncisco. I would bolt them solid like a Mopar.

Umm, regardless of location, I don't think I'd call it a "good mix"...;)

Thats what happened to ours , it just ripped the polly pad appart , i just made my own out of aluminum , i just figured out what degree i needed and machined them on the milling machine . They look neat too .
Mark.

My 67 camaro came with mono leaf springs, the axle slipped forward on the left side.

Our second gen uses multi leaf springs with Hotchkis multi leafs. One thing I noticed on the chassis dyno was the axle rocked on the leafs when power was applied. I also saw this in the staging lanes at the autocross whenever the car was moved, I could see the brake caliper rotating with the housing. We had pads on the bottom and top of the leaf pack, with two 4 deg spring shims on top of the leaf to get the pinion angle correct. The spring shims were on top of the leaf, but they cut into the top pad, and the thickness of the shims prevented the leaf center bolt from engaging at the top. The only thing holding the rear axle was the lower nut, and it barely caught the edge of the lower hole. Looking up into the hole I could see it slipping past it.
David

You can see in this photo, the bolt head does not stick down past the poly pad. It may be hanging on by a thread, but not enough to stay. With two angle shims on top, the top end of the bolt does not protrude beyond the shims, so this photo shows all we had holding it at the bottom. The poly "cap" has allready sheared off, and the nut is slipping past the hole.
http://i117.photobucket.com/albums/o71/davidpozzi/Other/lower_bolt_offset2.jpg
http://i117.photobucket.com/albums/o71/davidpozzi/Other/ring_pad.jpg

Thanks David ,I did not use the gold bushing and cut off the tip of the Iso. pad so I could see the align. nut and did get it to protrude through the lower shock plate ,but the lower Iso. pad is squarming around (moving)only after maybe 25 miles on my car,and all is still tight, so out it comes....It must be a problem that Hotchkis figured out or many calls to Drew,He said to eliminate it ,I wonder if this thread needs to be a STICKY,for safety reasons ....Safety first above all...and then Happy Motoring :)

Jerome,
Not a bad idea to make this a sticky,I hate to put too many stickies up there, but this one will probably generate interest.

Lots of pitfalls in this area. If given half a chance, the spring will want to slip.
David

This is the other thing I was thinking about why I left out my top pad. I have universal spring perches like in the picture. If I put the pad on top even if the alignment nipple suck through I'm leary about the rear still moving. Remember the stock perches wrap around the spring preventing it from sliding side to side even if the nipple isn't in the hole. I think its much safer if the rear is directly on the spring and tightend down with 1/2" U-bolts. No chance of play. Thats my thinking at least.

I have a pair of those for my 67 but not on yet. With them the U bolts will be much easier to put on and I'm also using the circle track type shock plates which are thicker but smaller across.
David

Thanks David ,this may save guy's (and gal's) time in a long run, not taking there rear back apart to get them out ,or worse the rear shifting and something happening that wouldn't be good,I am even thinking about the Alum shim deal on top,Happy Motoring Jerome

Ive run them both ways in my car. When the car was set up for street/strip with a 12 bolt there was some noise, I just cut a pad the size of the mount out of a truck inner tube and it quieted it down. When I switched to a 9" (universal mounts) I didnt run any pads on the mount with either a Jbolt traction bar or a ladder bar.
car is being torn down and returned to street, I will not be running pads other than an aluminum shim for pinion angle.

When installing my Moser I couldn't get the u-bolt nuts tight. I was distorting the lower plate and bending the u-bolts and still not getting the nuts tight. After a 3 mile drive I could at least 3 full turns on all 8 nuts before they would even snug up. I pulled all the rubber pads out, used new u-bolts and nuts, beat the lower plates flat again, and was able to torque the new nuts to 40 ft lbs. 1500 miles later and they are still tight.

Another problem with the mono leaf shock plates, is - they are thinner than the multi-leaf plates and bend quite easily.

When installing my Moser I couldn't get the u-bolt nuts tight. I was distorting the lower plate and bending the u-bolts and still not getting the nuts tight. After a 3 mile drive I could at least 3 full turns on all 8 nuts before they would even snug up. I pulled all the rubber pads out, used new u-bolts and nuts, beat the lower plates flat again, and was able to torque the new nuts to 40 ft lbs. 1500 miles later and they are still tight.

Whats the correct torque? I put mine at 85 ft lbs. I got some big U-bolts.

I was bending the 1/4 inch plate steel multi leaf brackets. Every time I took everything back apart the nuts would gawl on the u-bolts and I would have to get out the hacksaw.

At least I found a place in Sacramento that makes u-bolt while you wait!

Whats the correct torque? I put mine at 85 ft lbs. I got some big U-bolts.


Lots of torque, what is going on inside the axle tube with these u-bolts? I have see some tubes with half round knotches in them when the bolts are removed and you can see this inside the tube with the axle out.
I am using poly pads with the round spacer bushing outside the nut and no issues. Course I may not have a 550 hp motor either with 14" wide tires.

Looking at the round bushing and split rubber thru the lower plate, any chance of that bolt and nut , NOT going thru the plate hole to keep the center aligned? Could the lower plate hole be too big?

I asked about the Pinion angle he said the kit will not change pinion angle and not to worry 1.5 in drop is not enough to change the angle ...Happy Motoring

Hes right, the pinion angle will not change, but the drive shaft angle will! I'd go with D. Pozzi on this one: the pinion angle will have to be corrected for the new drive shaft angle.

joe c

http://i217.photobucket.com/albums/cc96/tamjss/cars3-17-08002.jpg
http://i217.photobucket.com/albums/cc96/tamjss/cars3-17-08001.jpg

Hi all, sorry it took so long to post these picture's but this was my answer to the problem of the lower iso and the space between the lower shock bkt. And upper leaf spring bkt. There are 5.25 long x 1.4 wide and .500 thick ,the hole's are 3.5 apart and measure in .6 from the side that will go against the spring. Now they can be torqued (also took the lower short leaf out car looks like it sits a little lower ),I left the upper iso. In ,I was going to make a spacer to replace but didn't think it was needed ,hope I did the right thing ,and don't half to tear into in the future… Happy Motoring..P.S The iso. pads only had 20 miles on them and already looked like crap..hope this helpes in the future for anyone doing the TVS kit..

This is a good thread. I have my diff housing out for sandblasting/painting, and it's almost ready to re-install. Upon diff removal, I examined the iso pads and saw shifting problems, similar to David Pozzi's pic.

I need to use a 2 degree shim to move pinion angle up, but I'm unsure about using my brand new iso pads now. It seems like a crappy design, lol.

Does anyone have the "Goldilocks" solution here? :confused::confused::confused::confused::confused: :confused::confused:

It seems like there's lots of different opinions unfortunately......I like the idea about milling a custom alum pad, with the 2 degrees built in. I also like idea about just using piece of heavy inner tube.

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I had no issue's with vibration with my current rear setup(per Hotchkis tech Drew doing this TVS kit should not change your original(OEM) pinion angle) and my PG trans ,but I am going to TKO600 so I will check pinion angle and adjust accordingly if needed…Happy Motoring

David Pozzi, what is your solution to this issue? Can you post a pic of your setup?

thanks

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I have been driving without the pads since I posted this and I am happy with the way it drives.

I have trackbite leaf springs (mopar style leaf setup) that has 5 leafs and another half leaf that runs to the front that acts as a traction device. I installed them with poly pads upper and lower. The rear never felt solid...aways seemed to be moving around during hard driving. When replacing the rear last summer the pads showed the same wear that others here saw. The rear was moving around! Some of that I figured was due to using both pads which was to much for to little space.
For the new rear I decided not to use the upper pad but wanted to retain the pin locator in the spring perch similar to the mopar style. I welded a 1/8" plate flat in the perch and drilled a 7/16" hole in the center to match the pin size of the spring. I used new rubber pads on the bottom. No movement now and everything fits.

http://i21.photobucket.com/albums/b290/Orange71/DSC04474.jpg

http://i21.photobucket.com/albums/b290/Orange71/DSC04748.jpg

For the new rear I decided not to use the upper pad but wanted to retain the pin locator in the spring perch similar to the mopar style. I welded a 1/8" plate flat in the perch .......

It looks like a thick piece (or half-leaf) at the top of the stack???

Are those 1/2" u-bolts? Where did you get them?

Thanks

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It looks like a thick piece (or half-leaf) at the top of the stack???

Are those 1/2" u-bolts? Where did you get them?

Thanks

-

That's the half leaf that runs to the front and wraps around the front spring eye.

I got the 1/2" u-bolts from: http://www.totallystainless.com/totally.html

I got the 1/2" u-bolts from: http://www.totallystainless.com/totally.html

Thanks, it looks massively strong with 1/2" u-bolts.