I have an Automatic 86 Camaro, 2.8L. Sometimes when I'm accelerating in 4th gear the car has a really nasty vibration. When I'm just at a crusing speed I can usually find a point when the car doesn't vibrate, but once I add a little gas, it usually starts shaking like crazy. If itdrops down in to 3rd its perfectly fine. There aren't different severities of shaking, it either is shaking like crazy or running smooth. Am I looking tranny issue, like somehow 4th gear is maybe slipping or something? Or is something entirely different? Any ideas?

Thanks Guys.

 

My IROC has been doing that for a while now too. Shakes like crazy when you push on the gas a little while cruising. Sorta like driving over a cattle guard, right. I think it's the converter or more specifically the clutch in the converter. Try this on your car. Make it shake and while its shaking press slowly on the brake pedal. Touching the brakes will disengage the lock up in the converter. Mine won't shake when the brake pedal is slightly depressed. If yours is like mine, we both need to change our torque converters.

 

When it happened in my bird it was the driveshaft. No problems in the TA with an aluminum driveshaft.

 

redliterunner, Thanks for the tip. I'll try that tonight after work and let you know how it goes.

 

Actually, after you mentioned the torque converter as the problem I did some research on that and I found this site, that is a combination of threads on this issue. The "Cattle Grid" problem as they call it. It describes my problem perfectly.

http://www.fordscorpio.co.uk/cattle.htm

The following is a quote summerizing the problem from the website, yes they are talking about fords and its a british site, but its likely similar:

"Owners have reported that the symptom is well recognised by Ford technicians as the Cattle Grid effect, and it has been reported that a seal ring in the Auto Fluid Pump to the torque converter wears unevenly and causes fluctuations in the TC or TCC. Several owners have reported that a renewal of the torque converter has cured the symptom. A repair of this nature has cost owners in the region of £600 including labour, excluding VAT."

If this is indeed the problem, any idea how much it would cost to get this fixed?

 

Well, in my case it's going to cost about 1800 bucks, because I'm doing the whole G-Gorce 5-speed thing. However, I suspect the fix could go pretty cheap.

Lowest estimate: IF you were able to get a good converter out of a salvage yard for 50 bucks or so, borrow a garage, floor jack, and jackstands, you could get the transmission out yourself, change the converter, put it back together, change the fluid and filter and be done with it. About 70 bucks, a couple of bloody knuckles, and it might just work! Getting the tranny out and back in is not that hard, it's just heavy and dirty work.

Middle estimate: Buy a new or remanufactured converter from your local autozone or equivalent for 150 bucks or so and take it to someone to have it installed for another 200-300 if your installer is honest. He'll probably want to change your fluid and filter, and flush your transmission as well. More money, but you'll save the cost of band-aids.

High estimate: Drive your car to the tranny shop, bend over, and tell them to fix whatever's wrong. Sky's the limit with this scenario. You could easily spend over 1000 clams, but you'd get a warranty.

If it were me, I'd go get the new or reman converter and get under the car.

All this is of course assuming that the converter is the problem in the first place.

One last thing: Though I feel like these guesses are in the ballpark, my wife says that I always underestimate the cost of stuff for the cars by about half. (I told her about 900 clams on the 5 speed swap.......shhhh)

 

Well, until I happen to trip over a big bag of money, I think I'll just live with the vibrations, I've learnt to deal with it. As long as it doesn't cause any more problems other then the annoyance of it, I think I could live with it. (I'm not quite at the automotive knowledge state where I can be ripping apart my tranny.)