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MG TD TF 1500 - 'P' factor?

Here's a question for you. When driving about over about 45 mph or over on a straight road when I take my foot off the gas the car wants to aim itself a little bit to the left. Nothing drastic, but a bit worrysome. When I hit the gas again it goes back to the right. The faster I go the more pronounced it is. I don't think it's in the steering because I feel no sensation in my hands on the wheel when this happens.
In the world of single engine prop planes I would call this P-factor (actually, reverse P factor). My U-bolts are new and just re-tightened. Rear springs totally rebuilt. Engine stabilizer rebuilt and installed correctly. Engine mounts brand new. All suspension and steering bushings, bolts, etc. are brand new. Everything should be tight. Tires are worn evenly. Front end allignment is good.
Any suggestions of things to check? (And please don't tell me to add a little left rudder!)
Regards,
Ed
efh Haskell

Just wing walk,Ed. Seriously though, if you don't feel it in the steering, it pretty much has to be in the rear suspension. Look again at all rear bushings and attachment points. Might also do your exam with the axle in weight bearing mode as well as with it against the travel stops. Some stuff tough to spot when the vehicle is lifted into an un-natural position. Betcha find it in the hind end. Dan
Dan Craig

Hello Ed. What you describe are the symptoms of a differential moving. The usual fix is to tighten up the u bolts holding holding the differential to the springs. While you are down there check that the u bolts are not worn where they go accros the top of the differential housing tube and that grooves have not been worn into the tube(I've seen it where the tube was worn nearly thru the axle housing). Also check the condition of the rubber pads that support the axle housing.
Since you say the u bolts are new and retightened I would look at the rubbers bushings in the springs.

Butch Taras
Glendale Ca.
VMG
TD Y MGBGT
R Taras

Ed,
Dan and Butch are "spot on",,, when I put new rear springs on our TD, it took a few short trips with tightening after each trip to make the U Bolts tight... Make sure that you loosen the lock nut first, then tighten to first nut...followed by re-tightening the lock nut again,,,

SPW
STEVE WINCZE

Yep...rear U bolts fixed mine...
gblawson(gordon- TD27667)

Rear end eh? Well, I personally just rebuilt the rear springs with ALL new rubber parts from Moss. All new bushings that hold the springs to the car. The only parts reused were the leaves themselves which I blasted and painted. The U bolts are brand new and have the piece that prevents groves from being worn in the axle. I've already retightened them with no effect. The leaves no sign of lateral movement. I've checked all this with the wheels on the ground. Do you think putting it on jack stands would show different results maybe?

For the engineers out there. Curious why the rear end would cause this effect? Is it because it's turning rapidly inside under load and when you remove that load (i.e. take your foot off the gas) there is energy built up that has to go somewhere? Just a guess.

(Yea, I know the U bolts are upside down in this picture. It was just a photo op. And I meant right rudder, not left. It's been a while.)


efh Haskell

ed, just curious if anyone else drives your car, and if so, if they notice the same thing...perhaps let them drive it WITHOUT suggesting what they are looking for.
i know when i put a car back on the road every thing is noticed..real or not. regards, tom
tom peterson

This thread was discussed on 29/09/2011

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