Pulsing/Shuddering when accelerating
 

1985 Carrera

When letting out the clutch while going around a turn? Don't have the same feeling when going in a straight line. Kind of feels like the clucth may be having problems getting a grip on the pressure plate, but why only when I am turning? Doesn't make sense, as the clutch was replaced less than 20K miles ago.

Could this be the early warning signs of a CV joint? It doesn't happen when I am driving or accelerating in a straight line. Also, when I push in the clutch at speed and just roll along, I hear no noise at all.

I pulled on the top of each of the wheels to see of they were loose, and none were.

I did just change to Redline transmission fluid this weekend, and I don't know how that could make a difference?

if you have positraction, and it doesn't like your new gear oil, you get a groaning and slight shudder on turns. posi units like GL-5.

Hmmm.It is a GL-5 rated oil with a 75W90NS rating. http://www.redlineoil.com/products_gearlubricants.asp?pvID=82&prodID=60&subc atID=20

I am wondering if I should have went with the 85W140 oil as some of the people have mentioned doing. Honestly, I need to find out if I have posi.

Bill - how ironic it would be if changing your oil (albeit gear oil) caused problems for you. You didn't use synthetic did you ;)

p.s. I like your idea of opening a decent service oriented shop here on the Peninsula.

Bill

Bill, I did in fact use synthetic - Redline to be exact. I am trying to see which oils make the gear box feel better without going broke. I used Swepco a few times, but it was always balky and unreliable when cold - why should I have to wait for it to warm up?

The oil before the redline was plain Valvoline Gear oil, and to my amazement, it looked almost as good as the day I put it in.

Swepco prices have hit the roof ($50 for a gallon versus $30 for Redline)), which I think is crazy as it's basically petroleum oil marketed for boilers and tractors and milk trucks :)

Now this pisses me off about this Redline. I think I may drain it this weekend, and go back to Valvoline - it actually worked perfectly.

any report, eurocarrera?

My car does this too because the limited slip is grabbing "too much". My car has a 40% limited slip, but the trans has been rebuilt at some time so it might have been shimmed up. I know the car is up to date on fluid changes, but I'm not sure what the PO's mech put in (need to look at the receipts).

I'm curious because I would like to reduce the grabbing. I would consider using valvoline and "doctoring it up" to my satisfaction after the fact using an additive.

Thanks!

edit: eurocarrera never responded but here's a subsequent thread:

http://forums.pelicanparts.com/porsche-911-technical-forum/159950-915-miracle-juice.html?highlight=dow