Axel hop

[wcdeane]

Has any one out there ever experienced or devloped axel hop in a 89-94 Esprit SE? And if so, have you learned anything about the cause and/or the solution?

[cnh1990]

Like as in going around a bumpy turn at high r's in 2nd gear?
Calvin

[gumbiner]

is it hapening only when you corner?

[lotusguy]

Has any one out there ever experienced or devloped axel hop in a 89-94 Esprit SE? And if so, have you learned anything about the cause and/or the solution?

WC,

What you describe is often a symptom of degraded radius arm insulator/mounts. These are often overlooked, but do degrade with time. The extreme heat on the driver's side causes the rubber to harden and possibly even tear reducing the tension they are meant to transmit to the radius arm.

They're not too expensive, and not too difficult to replace, although the driver's side can be a little challenging. Be sure you have a floor jack so you can 'tension' the new ones when reinstalling . You merely raise (compress) the suspension with the floor jack under the rear shock, then torque the insulator/mount to spec. Hope this helps. Happy Motoring! Jim'85TE

[johnny boy]

Is this similar to what I sometimes get?

IE accelerating hard and going over a pot hole causes a very loud bang from (what sounds like) the rear suspension.

The car is only 15 months old with 16K miles

Regards

John

[wcdeane]

It happens on straight and hard acceleration.

I had just come out of winter storage after a few upgrades. Basically, three things changed. I replaced my back tires...Dunlop SP 8000s. They seem to hook really well, but I didn't notice any hop after this upgrade alone. I also upgraded the chip to a MC high torque chip. This is a great chip, and the torque and performance is something to behold, but no hop after this upgrade either. The last thing that I did was open up the exhaust. I eliminated the EBPV and installed my own low restriction “Flowtech” muffler. On my first test drive I could tell instantly that I got a bunch of torque out of this mod. The acceleration was very hard. I would start rolling in first gear and just punch it. I’d get hard acceleration at first, then the hop would set in as the RPM and torque went up, and then I would have to back off. It was very violent. The kind of hop you might expect on a leaf-spring American mussel car -- not on a refined car like this. I checked things out afterwards, and everything looked fine. Now, I think that I understand the physics of axel hop. I just don’t understand how it could possibly occur on one of these cars, with the way the rear suspension is designed.

There’s more. This car has Carrera coil-over shocks. I had been tweeking the suspension on all four corners all winter – adjusting the height – swapping springs in and out. The axel hop occurred with 325#/in. rear springs. I swapped in a pair of 425# springs, and it seems to have cured it. I’m satisfied with the outcome for the moment, but I’m not sure about what lession I’ve learned. Comments/speculations are welcome.

Walt…’91 SE