Chasing an Issue on the LR/RF

[missile07]

I have had several people private message me and I am very open to any and every option of trying stuff. Several have asked about checking birdcages, rod ends, j-bar, torque arm while it has a load on them? Other than just replacing with new parts how would I go about applying a load and checking these parts?

[fastford]

Yes he finished the race with the bent shaft (bent down near the rod end) and yes the car would continue to climb the bars...like I said in the original post, if he is on a tacky track the car will hike once it hits traction but will not otherwise & will not leaving the pits, & not at all in the slick.

We are on a chain and we went ahead and checked the motion on it as well.

I can easily lift the LR of the car from ride height to near full travel by picking up on the bumper & I can easily push the nose down on the RF to full travel. But own its own the car cannot lift in the LR. We feel like something is binding once there is a load applied to it.

this rules out a lot of thoughts wreck related , now like has been mentioned , if a moving part got damaged , then it might have still worked for the rest of that race and seized up later , IE: a damaged rod end or bird cage bearing could cause this....JMO...

[missile07]

A true triple stack (3 separate springs). It has been checked and nothing seems wrong there. Took all 4 4 link rods off and replaced, took 5th coil shock off and replaced & ran torque arm thru the motions and nothing. Going back at it tonight. Pulled axles out to make sure that they come out easy.

Nearly ruled everything out other than brake fluid and lower radiator hose!!!

[Jking24]

I would definitely look into the drive shaft situation as mentioned. Also you say you have a "triple stack" is it a two spring stack with a take up spring or a true three spring setup. If it is does it have multiple lock outs and are you sure the stack is still operating as it originally was.

[MachineMasters]

Rod ends can sometimes rotate free with no load and then bind up with load. If you have a smash machine, put a 4 link rod in and compress to 1500lbs and make sure you can still turn the rod ends by hand.

I'd pull the driveshaft out and make sure the ballspline or slip yoke can move into the transmission with little resistance.

Double check the bearings on the LR shocks.

Ensure the sliders on the LR shock behind aren't binding or catching on the shock body - can look fine on a machine when the shock is straight up and down but when installed can bind from the shock angle.

The static LR load number looks low in my opinion. Raising that up to 600lbs or so should make the LR want to extend easier from ride height, depending on how the stack is setup.. A common LR load at static height would be in the 600-700lb range. I like your extended load range.

[missile07]

Yes he finished the race with the bent shaft (bent down near the rod end) and yes the car would continue to climb the bars...like I said in the original post, if he is on a tacky track the car will hike once it hits traction but will not otherwise & will not leaving the pits, & not at all in the slick.

We are on a chain and we went ahead and checked the motion on it as well.

I can easily lift the LR of the car from ride height to near full travel by picking up on the bumper & I can easily push the nose down on the RF to full travel. But own its own the car cannot lift in the LR. We feel like something is binding once there is a load applied to it.

[Dirtslinger20]

I’m assuming you’re using a chain as a Limiter.... might sound a lil crazy, but a local guy here fought a similar problem with not getting any hike at all at times.... his chain was catching the axle mount and binding up

[fastford]

The wreck happened on a restart...leader brake checked we were second and the third place car ran up under him & picked his rearend up off the track. Finished the race with the bent shaft.

We decided over the weekend that we will are going to take rearend out of the car and make absolutely sure there isn't a bent axle tube, etc.

I should have more info in the morning.

so you finished the race with the bent shaft ? was it getting up on the bars after the wreck or did it start staying flat right after the wreck ?

[dirtrace09]

With the rearend out check all the heims, birdcages and the rr shock. Don't forget to check the lift arm heims as well. I hope you find the issue. These things can be very frustrating.

[missile07]

The wreck happened on a restart...leader brake checked we were second and the third place car ran up under him & picked his rearend up off the track. Finished the race with the bent shaft.

We decided over the weekend that we will are going to take rearend out of the car and make absolutely sure there isn't a bent axle tube, etc.

I should have more info in the morning.

[MachineMasters]

Sounds like there is little to no compression bleed in the shock. I'd verify with the shock builder that the bleed size did not change at all.

4-link rod ends - did you replace them? If the hit was in the rear a rod end (or two or more) may have stretched and is now binding under load.

Measure rear end straightness? Wouldn't explain the Integra fixing the problem but if the rear end was bent badly..

[MasterSbilt_Racer]

Yes we are dealing with the original builder of the shock. The original builder replaced the bent shaft and said everything else looked fine. Swears he did not change anything other than the shaft. We tried it and it will not hike in the LR. Took it a to a local shock guy to look at and he talked with our original shock guy and says it looks fine to him as well. Still nothing.

When I say the car sits higher in the LR and lower in the RF we thought maybe it was an optical illusion because we just put a new body on it but its not. The car will not settle in the LR. We left it sitting over night Friday night at ride height and come back Saturday morning and it had dropped from a spoiler height of 41" to 38.5". Shock mounts have not moved.

We are going to basically strip the car to the frame and make sure we haven't missed something. Just frustrating

Birdcage bearings?

[dirtrace09]

Tell us about the wreck that bent the shaft. Where on the car did it take the hit? Also, how did the car move when it was hit? I am guessing another corner took some of the brunt of the impact (even if it wasn't the direct hit) and is possibly the culprit.

[missile07]

Yes we are dealing with the original builder of the shock. The original builder replaced the bent shaft and said everything else looked fine. Swears he did not change anything other than the shaft. We tried it and it will not hike in the LR. Took it a to a local shock guy to look at and he talked with our original shock guy and says it looks fine to him as well. Still nothing.

When I say the car sits higher in the LR and lower in the RF we thought maybe it was an optical illusion because we just put a new body on it but its not. The car will not settle in the LR. We left it sitting over night Friday night at ride height and come back Saturday morning and it had dropped from a spoiler height of 41" to 38.5". Shock mounts have not moved.

We are going to basically strip the car to the frame and make sure we haven't missed something. Just frustrating

[MasterSbilt_Racer]

Looking for advice....knowledge...help

Bought a new car this spring & won several races straight out of the box. Anytime we were loading the car in the hauler or in the pits and he turned the car to the left it would instantly lift up the left rear and smash the RF nose to the ground. The car sat up really high in the RF and squatted in the LR. The car had a 3 spring LR stack with no lock out nut that came out to be roughly 40lbs.

Got in a wreck one night and bent the shaft on the LR shock(Bilstein). Sent the shock back to the builder and got the shaft replaced & sent back. From then on the car will not get up on the bars. Will not pick up at all when moving in the pits and more importantly on the track unless it in hammer down traction. Now the car sits higher in the LR and lower on the RF

We assumed we had something else bent. Changed out complete RF suspension, checked birdcages, checked 4 links bars, etc.....found nothing else bent or binding.

Not exact numbers but our smash numbers are:
RF 700 @ 19" 2050 @ 14.25" 200 lb single spring
LF 600 @ 17 " 350 single spring
RR 350 @ 20" 250 single spring
LR 420 @ 20" & 165 @ 24"(dropped out) * triple stack at roughly 40lbs WITH lockout nut

Will not climb the bars. Bar angles are the same. We have tried the triple stack without the lockout nut, added gas 150psi to LR shock, we have changed RF shocks & lowered compression & load down to 675 @ 18".

I can walk up to the RF nose and barely put pressure and it goes to the ground. I can go to the rear bumper and with one hand lift the LR to near full travel but on its own it will not lift. I can jump on the rear bumper and the car will not go down on the left rear.

One night out of desperation, I grabbed a older spare Integra LR shock with a 125 spring for our other car and stuck it on. Car lifted LR, wrinkled the tire and slammed the RF nose down.

Two different builders have looked at the LR shock(Bilstein) now and both say it looks fine.

What are we missing?

If your car sits different at static ride, the loads are different. Shock mount change or way more rod pressure in a shock could explain it.