Jump to content
SAU Community

Recommended Posts

First off, I think you need to confirm you actually have axle tramp.

My understanding is that the driven tyres lose traction when you apply too much engine torque to, and the wheels simply bounce up and down. It's far more comon in leaf spring setups. That is why I couldn't believe that new Bilsteins and Kings springs didn't solve the problem. And since no-one has actually seen what is going on when you get the "axle tramp" happening.

What did the guys at Traction have to say about the likelihood of you having "axle tramp"?

  • Replies 41
  • Created
  • Last Reply

Top Posters In This Topic

Pat as a last resort try fitting adjustable rear traction arms.

Youll need camber arms to go with them, and from my understanding you should lengthen the traction rods an amount to acquire more grip.

Have you fixed that vibration yet?

Just a thought, it could be your universal joints in the tailshaft? Or the tailshaft itself? I had a lot of bouncing around (like a constant shuddering until I had pretty much shifted into 2nd gear) under there when launching so got it up on a hoist and someone identified to me that it was the tailshaft bearing.

I went to get that replaced and they also ended saying that all the universal joints were rooted!

I ended up getting a 1 piece tail-shaft and this has fixed all my vibrations when launching.

Edited by -Jimmy-

You have forgotten the basic laws of mechanical diagnosis, get the basics right then go from there. In other words your car is ancient in regards to your stock bushes so you might want to replace everything you can with urethane. I have said it before and will repeat it yet again, your differential is in the center so replace those bushes first. Every time this comes up the first thing someone suggests is the springs and shocks and yes it may well be but I can tell you now your differential bushes are flogged to death, replace them. Unfortunately it is a diff out situation for the rear bushes but at least do the front ones closest to the drive shaft. Think about how many times you accelerate and back off and how the diff goes up and down with it and you can see my point. If a stock car with new bushes everywhere doesn't axle tramp ( and yes I know some do but not skylines ) then right there is your answer, things have worn.

What did the guys at Traction have to say about the likelihood of you having "axle tramp"?

At the time i went to show Traction Tyres, the roads were wet and they didnt want to test. Will go back to them once the roads dry up.

Just a thought, it could be your universal joints in the tailshaft? Or the tailshaft itself? I had a lot of bouncing around (like a constant shuddering until I had pretty much shifted into 2nd gear) under there when launching so got it up on a hoist and someone identified to me that it was the tailshaft bearing.

I went to get that replaced and they also ended saying that all the universal joints were rooted!

I ended up getting a 1 piece tail-shaft and this has fixed all my vibrations when launching.

Ive had the tailshaft pulled off and rebalanced so definitely not that, could be the surrounding joints/bearings though...

You have forgotten the basic laws of mechanical diagnosis, get the basics right then go from there. In other words your car is ancient in regards to your stock bushes so you might want to replace everything you can with urethane. I have said it before and will repeat it yet again, your differential is in the center so replace those bushes first. Every time this comes up the first thing someone suggests is the springs and shocks and yes it may well be but I can tell you now your differential bushes are flogged to death, replace them. Unfortunately it is a diff out situation for the rear bushes but at least do the front ones closest to the drive shaft. Think about how many times you accelerate and back off and how the diff goes up and down with it and you can see my point. If a stock car with new bushes everywhere doesn't axle tramp ( and yes I know some do but not skylines ) then right there is your answer, things have worn.

thanks for help.

I'll look into replacing the diff bushes.

Would anyone have part numbers of the specific bushes I would need to buy?

SuperPro SPF2637K RR Diiferential pinion mount bushing?

Any other bushes I should replace along with that?

Thanks all!

At the time i went to show Traction Tyres, the roads were wet and they didnt want to test. Will go back to them once the roads dry up.

Ive had the tailshaft pulled off and rebalanced so definitely not that, could be the surrounding joints/bearings though...

thanks for help.

I'll look into replacing the diff bushes.

Would anyone have part numbers of the specific bushes I would need to buy?

SuperPro SPF2637K RR Diiferential pinion mount bushing?

Any other bushes I should replace along with that?

Thanks all!

Not sure if that's the one but just ring the various bush suppliers and ask them to make absolutely sure. If you look under the diff you will see what I'm talking about. The ones at the rear are a pain as the hicas has to be unbolted and left to the side. I did this myself and takes a while to undo the drive shaft and axles but I kid you not, this totally eliminated my axle tramp.

I tried tyre first and that made it worse. Then springs and shocks, which helped a little. Replaced outside arm bushes after suspension proved to be giving too much positive camber, slightly improved but if on the edge of traction would shake violently. Was going to replace tie rods with rose joints but stopped off at a place with quite a few race cars out the front and made some inquiries, they said what I just did, start at the center and work your way out. As the old guy there said, "a building is only as strong as it's foundations". If you start with your tyres you will be chasing your tail looking for the culprit. Get the diff nice and solid first. :P

just because a suspension place fitted your springs and shocks doesnt necessarily mean that the shocks and springs are matched for one another, so i wouldnt quite knock option 4 on SK's list off...

Axle tramp is caused by oscilations in the vertical direction of the tire, spring and damper system. Majority of the time its caused by the shock absorbers lack of control in rebound to "dampen" these osciallations as SK has stated.

I too have this problem, have SK's full suspension kit and are looking for answers...my thoughts are leaning towards either my springs, or the position where my subframe bushes are placed. There are a few alternate configurations for these bushes to be arranged in and i believe my current setup is for "All round performance"...I would think positioning these bushes to achieve more squat (or reduce anti-squat) would be a cure, as to increase longitudinal load transfer (for and aft of the car) to the rear, and hence increase the vertical load on the rear tires. If i find a fix, ill let you know Renkin

i can tell u, i still get axle tramp in my car which is running valving designed for springs up to roughly 7kg on the rear, and is only running 4kg springs, so well and truly damped. this was the same with when i ran 5kg springs on those shocks, 4kg on the standard B6 shocks, and when i ran just the kingies on the bilsteins.

at every height, etc etc. its never completely gone.

i can tell u, i still get axle tramp in my car which is running valving designed for springs up to roughly 7kg on the rear, and is only running 4kg springs, so well and truly damped. this was the same with when i ran 5kg springs on those shocks, 4kg on the standard B6 shocks, and when i ran just the kingies on the bilsteins.

at every height, etc etc. its never completely gone.

There are plenty who don't get axle tramp, so there is something wrong with yours, you just haven't found it yet.

Cheers

Gary

yeh, that's what im saying.

i also have urethane subframe bushes, soon to be pissed off and replaced with solid mounting. ive run the car at anywhere from 300mm to 400mm, ive run anywhere from 20psi to 45psi.

it's lucky i dont give a shit about it otherwise id do my head in trying to figure out what the problem is.

just because a suspension place fitted your springs and shocks doesnt necessarily mean that the shocks and springs are matched for one another, so i wouldnt quite knock option 4 on SK's list off...

Axle tramp is caused by oscilations in the vertical direction of the tire, spring and damper system. Majority of the time its caused by the shock absorbers lack of control in rebound to "dampen" these osciallations as SK has stated.

I too have this problem, have SK's full suspension kit and are looking for answers...my thoughts are leaning towards either my springs, or the position where my subframe bushes are placed. There are a few alternate configurations for these bushes to be arranged in and i believe my current setup is for "All round performance"...I would think positioning these bushes to achieve more squat (or reduce anti-squat) would be a cure, as to increase longitudinal load transfer (for and aft of the car) to the rear, and hence increase the vertical load on the rear tires. If i find a fix, ill let you know Renkin

the shocks and springs were bought as a package from a suspension workshop. He sells plenty of packages for r33's/r32's so I have faith in his setup...As the problem didnt get better/worse after replacing from old suspension (kyb shocks w/ hks springs) I have a feeling its related to something other than shocks/spring setup...

Organising some diff bushes and will hopefully see some difference when replaced...

Will post details once they in :P

Thanks all

Well, you STILL haven't confirmed that you actually have axle tramp. It seems no-one has actually seen what is happening when you get "axle tramp". You have only felt something going on.

I just can't believe that brand new Bilsteins and springs are incapable of controlling the vertical motion of the rear wheels.

i got the SK kit on my r32 gtst with subframe bushes.

i get lots of axel tramp....its definitely that jumpy motion.

Its so violent that i have to back of the throttle because it feels like something will break.

I can confirm that have the whiteline bushes inthe max traction postion made it worse. The all round setup seems to help but only slightly.

I've also run, nexen cheap tyres, Re55's, 595RS, 595SS. The issue is only slightly different with each of these tyres.

Car is at ~350mm

my 2 cents......i will look into the diff idea.

hmmm I would have thought have a higher vertical load on the tire would improve the tramp. Drawing a diagram of the forces involved, if there is a higher vertical load on the tire acting downwards, for the wheel to oscillate or even travel upwards, the forces acting to push the wheel upwards would have to oppose a greater force downwards in this new subframe position. Strange :S

yogi have you tried the bushes in the opposite position, so in the max stiffness position (full anti-squat)? That might be something to try, however my thoughts would be that it may harm the traction of the car in all conditions of driving (wet, dry, damp etc). I find that i only get axle tramp in the wet, or in the dry when i put full boot into it doing a U turn.

It may not be diff bushes but I'll wager it is. I have owned my car for 228,000 of it's 250,000k's and I know it backwards after three engines and sorting it out through every little problem of it's mods. I have removed and replaced so many parts I have forgotten a lot of what I've done. Diff bushes.

If you look on the LS1 or Harrop site you will eventually come across exactly the same problem which was solved by installing a Harrop diff brace. Makes for interesting reading. Stop wasting money on shocks and springs and different tyres. Although, there is another way to fix it, set up a diesel spray above your rear tyres and mount the tank in the boot. Axle hop cured. :whistling:

I had the same problem with mine. did all the usual, springs, shocks (rebound and bump), tyres, pineapples in all positions, UJ's etc - no real change. Bought some Nismo HD engine mounts, 98% fixed. Still tramped a little but not the horrible banging in the rear and box. I know it sounds crazy but it worked for me.

J

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • From there, it is really just test and assemble. Plug the adapter cables from the unit into the back of the screen, then the other side to the car harness. Don't forget all the other plugs too! Run the cables behind the unit and screw it back into place (4 screws) and you should now have 3 cables to run from the top screen to the android unit. I ran them along the DS of the other AV units in the gap between their backets and the console, and used some corrugated tubing on the sharp edges of the bracket so the wires were safe. Plug the centre console and lower screen in temporarily and turn the car to ACC, the AV should fire up as normal. Hold the back button for 3 sec and Android should appear on the top screen. You need to set the input to Aux for audio (more on that later). I put the unit under the AC duct in the centre console, with the wifi antenna on top of the AC duct near the shifter, the bluetooth antenna on the AC duct under the centre console The GPS unit on top of the DS to AC duct; they all seem to work OK there are are out of the way. Neat cable routing is a pain. For the drive recorder I mounted it near the rear view mirror and run the cable in the headlining, across the a pillar and then down the inside of the a pillar seal to the DS lower dash. From there it goes across and to one USB input for the unit. The second USB input is attached to the ECUtec OBD dongle and the 3rd goes to the USB bulkhead connected I added in the centre console. This is how the centre console looks "tidied" up Note I didn't install the provided speaker, didn't use the 2.5mm IPod in line or the piggyback loom for the Ipod or change any DIP switches; they seem to only be required if you need to use the Ipod input rather than the AUX input. That's it, install done, I'll follow up with a separate post on how the unit works, but in summary it retains all factory functions and inputs (so I still use my phone to the car for calls), reverse still works like factory etc.
    • Place the new daughterboard in the case and mount it using the 3 small black rivets provided, and reconnect the 3 factory ribbon cables to the new board Then, use the 3 piggyback cables from the daughterboard into the factory board on top (there are stand offs in the case to keep them apart. and remember to reconnect the antenna and rear cover fan wires. 1 screw to hold the motherboard in place. Before closing the case, make a hole in the sticker covering a hole in the case and run the cable for the android unit into the plug there. The video forgot this step, so did I, so will you probably. Then redo the 4 screws on back, 2 each top and bottom, 3 each side and put the 2 brackets back on.....all ready to go and not that tricky really.      
    • Onto the android unit. You need to remove the top screen because there is a daughterboard to put inside the case. Each side vent pops out from clips; start at the bottom and carefully remove upwards (use a trim remover tool to avoid breaking anything). Then the lower screen and controls come out, 4 screws, a couple of clips (including 3 flimsy ones at the top) and 3 plugs on the rear. Then the upper screen, 4 screws and a bunch of plugs and she is out. From there, remove the mounting brackets (2 screws each), 4 screws on the rear, 2 screws top and bottom and 3 screws holding in the small plates on each side. When you remove the back cover (tight fit), watch out for the power cable for the fan, I removed it so I could put the back aside. The mainboard is held in by 1 screw in the middle, 1 aerial at the top and 3 ribbon cables. If you've ever done any laptop stuff the ribbon cables are OK to work with, just pop up the retainer and they slide out. If you are not familiar just grab a 12 year old from an iphone factory, they will know how it works The case should now look like this:
    • Switching the console was tricky. First there were 6 screws to remove, and also the little adapter loom and its screws had to come out. Also don't forget to remove the 2 screws holding the central locking receiver. Then there are 4 clips on either side....these were very tight in this case and needed careful persuading with a long flat screw driver....some force required but not enough to break them...this was probably the fiddliest part of the whole job. In my case I needed both the wiring loom and the central locking receiver module to swap across to the new one. That was it for the console, so "assembly is the reverse of disassembly"
    • But first....while I was there, I also swapped across the centre console box for the other style where the AV inputs don't intrude into the (very limited !) space.  Part# was 96926-4GA0A, 284H3-4GA0B, 284H3-4GA0A. (I've already swapped the top 12v socket for a USB bulkhead in this pic, it fit the hole without modification:) Comparison of the 2: Basically to do the console you need to remove the DS and PS side console trim (they slide up and back, held in by clips only) Then remove the back half of the console top trim with the cupholders, pops up, all clips again but be careful at the front as it is pretty flimsy. Then slide the shifter boot down, remove the spring clip, loose it forever somewhere in the car the pull the shift knob off. Remove the tiny plastic piece on DS near "P" and use something thin and long (most screwdrivers won't fit) to push down the interlock and put the shifter down in D for space. There is one screw at the front, then the shifter surround and ashtray lift up. There are 3 or 4 plugs underneath and it is off. Next is the rear cover of the centre console; you need to open the console lid, pop off the trim covering the lid hinge and undo the 2rd screw from the driver's side (the rest all need to come out later so you can do them all now and remove the lid) Then the rear cover unclips (6 clips), start at the top with a trim tool pulling backwards. Once it is off there are 2 screws facing rearwards to remove (need a short phillips for these) and you are done with the rear of the console. There are 4 plugs at the A/V box to unclip Then there are 2 screws at the front of the console, and 2 clips (pull up and back) and the console will come out.
×
×
  • Create New...