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Author Topic:   RR Wheel Hopping
RangeRover
Dirt Maniac

Total posts: 174
posted October 03, 2002 06:29 AM
I need input on a problem I had this weekend with my Street Stock Chevelle. It's a pretty fast car and handles good, but I felt the RR shaking or hopping like crazy as I exited turn four and headed down the front stretch. Reviewing the video from the stands definitely showed the RR dribbling like a basketball for a little bit. It was frustrating to drive because I had to back off the gas so the tires could catch. I run DOT Good Years on MRT 8" rims with about 24 lbs. of air. The track is 3/8 and it actually stayed pretty tacky. The shocks are Carrera SS and only have about 8 races on them. The car weighs 3250 and I had the ballast up high and the car rolls over pretty good. It was fast, but I have to find out what the heck was happening and prevent it from happening again.
Any suggestions?

340duster
Dirt Full Roller

Total posts: 70
posted October 03, 2002 07:22 AM
My two suggestions would be: check for a clump of mud on rim (out of balance), or worn shock.

Geffy95x
Dirt Maniac

Total posts: 122
posted October 03, 2002 08:38 AM
Just what he said and as well it could be your shock is too far from your wheel so the rate would be too weak.

outlawstock17
Dirt Forum Champ
Total posts: 620
posted October 03, 2002 11:18 AM
yeah, a big mud clump will do that....on the front it'll shake your hands numb.

if it's not a bad shock or a clump of mud, it may be a tire spinnin' wheel hop thing. since you said that you had to back off the gas to let the tires catch, that's my guess. factory 4 links are known to have this problem. try lowering the lower control arm mounting point on your rearend housing, if your rules don't say that you can't.

widebody
Dirt Maniac

Total posts: 197
posted October 03, 2002 11:44 AM
If non of the other things check out look at your bushings on the rear control arms.
if a bushing tore out it will make a terrible hop...

racer17j
Dirt Forum Champ
Total posts: 1565
posted October 03, 2002 04:11 PM UIN: 54865418
one little trick to keep the mud thery here some hapening is to put a bunch of zip ties on the wheels when the wheel turns it will hit any mud out of the wheel we do this on the right side also spraying it with some wd40 helps too. you might also want to check that you don't have a slightly bent axle or wheel

RangeRover
Dirt Maniac

Total posts: 174
posted October 05, 2002 11:43 AM
These are good ideas guys, thanks. I looked at the shock mounting location, and it does look too far inboard. This was done to space it away from the chassis. I'll try to relocate it or maybe mount it further out on the housing end and leave the upper end where it's at.

teamstertom
Dirt Forum Racer

Total posts: 89
posted October 05, 2002 12:31 PM
I also had what I felt was a rr wheel hop problem a couple years back,and what it was in the end was a slightly bent axle. What surprised me more than anything,with the 10 bolts, when you bend that axle the seal starts to leak right away. One thing that I suggest is to take a moment and check those axles and seals if you are running a 10 bolt. It is only cheap insurance to do so.

RangeRover
Dirt Maniac

Total posts: 174
posted October 07, 2002 06:20 AM
As a matter of fact, it is a 10 bolt and I did just notice that RR is leaking. Doesn't look good. How do you guys check for a bent axle? Last time, I set a fixed pointer next to flange that has wheel studs in it and put the car in gear to spin the axle. Is this pretty accurate?

teamstertom
Dirt Forum Racer

Total posts: 89
posted October 07, 2002 04:52 PM
If you have any doubt about your axle being bent,that is after looking and doing all the simlpe tasks,bite the bullet,pull the cover,pull the clips, and check those axles. An rear end freshin'up just maybe in the works,seals,bearings,and lube. You can put a straight edge on those axles to check for trueness. If you run a higher banked track,you may want to check into a better axle. All this work will pay for itself in the long term. Money spent in the rear end,just may put you on the front end of a feature victory.

Geffy95x
Dirt Maniac

Total posts: 122
posted October 08, 2002 11:30 AM
Details Details Details.......cant win without them!!!!

RangeRover
Dirt Maniac

Total posts: 174
posted October 08, 2002 02:58 PM
The funny thing is, I did win that race, but I know it wasn't going to take much more. It definitely needs to be fixed for this weekend. Anyway, I put the car in gear while on jackstands and the wheels and drums off. The left side spun perfect, but the RR looked a bit shaky. What I mean is that it didn't just wobble rythmically; it kinda wobbled and shook a little erratically. I pulled the axle out and found the bearing very loose, almost as if one of the rollers was missing, leaving too much room for the rest and causing them to try and tumble instead of rolling smoothly. I'm wondering if the failed bearing caused the shake and compromised the seal. It's one of the non-tapered type bearings. I'm going to check the axle closer. It might not be bent. I haven't hit anything with it since I installed it last season. Anybody ever experience something like this?

teamstertom
Dirt Forum Racer

Total posts: 89
posted October 08, 2002 04:43 PM
The 10 bolt is a good rear end,not the best,but it will get the job done where as it may be what you have to run. I've see very lite rear wheel hits squarely on the tire and rim wipe out a axle and bearing. This happens alot with the pavement and enduro guys around these parts. Some people never pay any attention to the rear end,it is like the rest of your car,it needs alittle tender care once in a while.
Another area that never gets looked at is the area where the control arms go into the frame,look at the upper and lower areas. You might be surprised where some welding and gussets make be needed.

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