Excessive rear wheel "hop"
 

Hi all,
I don't know if you remember my '82 300D that I installed a 4.3L Astrovan V6 in? Well, I have a question for you! It's raining here in wet Washington, and I notice that when I depress the accelerator pedal too enthusiastically, the car "breaks loose", and I seem to get a lot of rear wheel hop, more than I remember last year, and more than when the pavement is dry. What are the various causes of this - do you think it needs shocks, or is it just the nature of the beast, or could the rear rubber mounts be getting worn, or what??
(Can't let those little Japanese roller skates get ahead of my "diesel" Merc! - HAH)
Thanks,
Richard Wooldridge
'82 300D/4.3L V6
Etc...

Insufficient damping in the wheel hop frequency range is the cause, and this is a common problem on high powered cars. Unless the body wallows around in normal driving the shocks are probably okay.

Consider that the currently installed engine has considerably more torque than the original diesel. The best solution is to be delicate with the throttle when conditions are wet.

Duke

Springs weak with age are probably the culprit...

do you have different tires on it than what you had last year? I've had several cars in the past that did this after I changed the tires to a different brand. At the time I assumed it due to different coefficients of grip (traction).

Same tires...
 

Hi there,
The tires are the same ones, but I have put around 75K on the car in the last two years. In the summer when it breaks loose it makes a more even "skree" type of sound, not much wheel hop at all. I do think the added torque has a lot to do with it, but also am wondering if some rubber parts could be deteriorating, as it does seem worse than last year.
Hey, Jetforeman, those Nissan pickups are made out of good stuff, I had one I put over 350K on before passing it along to my son. Also had several long-lasting Z cars, actually still have a 2+2 that I should get rid of, but it still runs like a clock.

Richard Wooldridge
'82 300D/4.3L V6
Etc...

Re: Same tires...
 

"Old Blue" (Nissan) is a tough cookie. I adjusted the valves on it last year for the first time in it's life!! And I barely had to make any adjustments.....And get this, last week I had an emissions check done on it and it blew cleaner than my E320 I just got rid of. I just shake my head in amazement and run the piss out of it. You would be surprised at how many people have stopped by my house in passing wanting to know if I would sell it. The answer is always and will always be a resounding NO!!