HOW TO DO AN ADVANCED SEARCH.

Mon Jul 08, 2013 3:56 pm by Admin


For the benefit of 944Hybrids users there are two search functions available for you to use.
The purpose of this sticky is to explain the "Advanced Search" function because it is much more powerful and is the best choice when researching information.

When you log on to the site a list of options is shown in a line at the top of the page. One option is labelled "Search", use this option (NOT the search box lower down on the right).

After you click on the upper search option, a drop down box appears. At the bottom of this box is a radio button marked "Advanced …

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Bump Steer Kit

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Bump Steer Kit

Post  pormgb on Sun Apr 01, 2018 12:16 pm

I thought I would share this in case anyone else has this kit.

Yesterday, after doing some exhaust clearance work, I pulled into my driveway and noticed my steering is very light and difficulty turning. Once I got my car into my garage, I turned the wheel and only the right side turned. Upon further investigation, I found the bumpsteer shaft sheared off right below the taper.

Here is a picture if the unit, I bought it from TPC in March or 2011, not sure how long these are supposed to last. I do not track events, just drive around town locally.


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Re: Bump Steer Kit

Post  matt889 on Sun Apr 01, 2018 9:31 pm

what torque spec did you use ? or it cut flat out ?

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Re: Bump Steer Kit

Post  pormgb on Sun Apr 01, 2018 10:37 pm

matt889 wrote:what torque spec did you use ? or it cut flat out ?

I torqued the nuts to 40ft lb, not sure what you mean by cut flat out.
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Re: Bump Steer Kit

Post  944-LT1 on Mon Apr 02, 2018 9:26 am

how does the spherical on that side look/feel?

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Re: Bump Steer Kit

Post  pormgb on Mon Apr 02, 2018 10:43 am

944-LT1 wrote:how does the spherical on that side look/feel?

Fine, moves freely. If I can get some 4140 chromoly Adapter Stud with the same taper, I will use my old spherical heims.

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Re: Bump Steer Kit

Post  sharkey on Mon Apr 02, 2018 12:32 pm

interesting break. couple thoughts

when tight, does the hex portion actually touch the steering arm? im wondering if the taper is fully seating into the arm

do you run misalignment spacers with the heim joint? if the heim joint bound up against the nut/washer at any point it could cause it to break.

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Re: Bump Steer Kit

Post  pormgb on Mon Apr 02, 2018 12:55 pm

sharkey wrote:interesting break. couple thoughts

when tight, does the hex portion actually touch the steering arm? im wondering if the taper is fully seating into the arm

do you run misalignment spacers with the heim joint? if the heim joint bound up against the nut/washer at any point it could cause it to break.

The taper looked fully seated, I tapped the broken piece out of the control arm and it was in there good, no gap between the hex and control arm.

I also don't think there was any binding, I would feel it in the steering. It snapped as I turned left and the tire hit the driveway curb.
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Re: Bump Steer Kit

Post  sharkey on Mon Apr 02, 2018 1:18 pm

if the joint was bound up on the spacers while the suspension is compressed you may not feel it in the wheel. with what you describe thats what i would guess happened.

if your gonna replace the pins (not go back to a normal tie rod) i would very closely check for binding. you might even want to go as far as taking the springs out and cycling the suspension to full travel and turning the steering lock to lock.

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Re: Bump Steer Kit

Post  pormgb on Mon Apr 02, 2018 1:32 pm

sharkey wrote:if the joint was bound up on the spacers while the suspension is compressed you may not feel it in the wheel. with what you describe thats what i would guess happened.

if your gonna replace the pins (not go back to a normal tie rod) i would very closely check for binding. you might even want to go as far as taking the springs out and cycling the suspension to full travel and turning the steering lock to lock.

I run 400lb springs up front and there is almost no spring movement at low speeds, there is no way the spring was compressed.

I have put back in stock tie rods for now, although the tie rods are at a terrible angle, I felt no bump-steer. I would have to be braking heavily or going over a bump at a decent speed to get enough suspension movement to feel bump-steer.

To be honest, I don't know if these kits are made from Chrome Moly, I know studs sold on Ebay are Chrome Moly and are IMCA approved.
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Re: Bump Steer Kit

Post  Hotrodz of Dallas on Mon Apr 02, 2018 2:17 pm

I've seen several of these kits break off just like that. Mostly when used on race cars. I've never had a stock tie rod end break. Most of the cars I've built and raced used the stock tie rods and never had a bump steer problem. Some of these cars are slammed very low to the ground. I personally won't use a bump steer kit.
My 2 cents anyway. Very Happy
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Re: Bump Steer Kit

Post  pormgb on Mon Apr 02, 2018 2:33 pm

Hotrodz of Dallas wrote:I've seen several of these kits break off just like that. Mostly when used on race cars. I've never had a stock tie rod end break. Most of the cars I've built and raced used the stock tie rods and never had a bump steer problem. Some of these cars are slammed very low to the ground. I personally won't use a bump steer kit.
My 2 cents anyway. Very Happy


Thanks for this, I ran the car with stock tie rods and found no issues.

I will scrap any ideas of reviving this kit or buying another.
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Re: Bump Steer Kit

Post  sharkey on Mon Apr 02, 2018 5:28 pm

bump steer kits from an engineering perspective is a big no-no. moving the tie rod down ends up putting more twisting torque on the steering arm, it also adds a point of deflection to the steering system. the proper way to fix bump steer is to either move the rack up (not always possible) or a steering arm lower on the knuckle.

in some cars its unavoidable to run a bump steer kit, i dont think our cars are one of them. lowering the subframe like most of us have done doesnt help, neither does lowering, however when i cycled my suspension without a spring in during my build i didnt see that much bump steer except for extreme limits of the suspension.

if i had to run a bump steer kit on a 944 it would likely be the elephant racing one. it doesnt change the fact that you are (in theory) adding twisting force to the steering arm, but it is a much better supported piece with the cage around the arm. its much better than just a pin.

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Re: Bump Steer Kit

Post  pormgb on Mon Apr 02, 2018 6:41 pm

sharkey wrote:bump steer kits from an engineering perspective is a big no-no. moving the tie rod down ends up putting more twisting torque on the steering arm, it also adds a point of deflection to the steering system. the proper way to fix bump steer is to either move the rack up (not always possible) or a steering arm lower on the knuckle.

in some cars its unavoidable to run a bump steer kit, i dont think our cars are one of them. lowering the subframe like most of us have done doesnt help, neither does lowering, however when i cycled my suspension without a spring in during my build i didnt see that much bump steer except for extreme limits of the suspension.

if i had to run a bump steer kit on a 944 it would likely be the elephant racing one. it doesnt change the fact that you are (in theory) adding twisting force to the steering arm, but it is a much better supported piece with the cage around the arm. its much better than just a pin.

Yea, I looked at the elephant racing kit but with so little suspension movement, I don't think bump steer will be an issue. I also noticed my steering to be more precise once going back to stock tie rods, that was probably due to the twist with the bump steer kit.
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Re: Bump Steer Kit

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