Gearbox Inquirery

[oldginger]

Hi, I am not sure if my GV auto gearbox is behaving. In the lower gears it seems fine but in the top gear it seems to suffer from some slip especially when accelerating from 50mph +.  Its a heavy car  so is this normal?  I have had a major service since buying  it due to no service history and I am wondering if a gearbox service is in order. Just to keep up with products, are the ATF VI oils by Dextron,Smith&Allen,etc, ok?. I have sorted some niggles due to this forum, lots of help and advice available so thanks to all. 

[QinteQ]

I only ever use Chrysler recommend oil which is ATF+4. It doesn't have to be their Mopar brand but I'd never put anything else in my friend. Ditto recommend engine/coolant/brake fluid even.

 

The tranny is a sensitive hydraulic fluid coupling / converter not just a lubricant. Best of luck.

[bignev]

Slip doesn't sound good, maybe some new fluid to drop out some of the dirty contaminated crud that might be getting in the way of the friction plates will help. A change of fluid certainly shouldn't make it worse!

 

Be aware though that even at somewhere between 4 and 5 litres of the ATF+4 you will only change about half of its capacity. Loads of fluid is retained in the torque converter, but you do NOT want to empty that - a whole world of mither will follow.

 

So if it helps a bit, and your wallet can stand it, do the change again a while later, after the new dilutes the old nicely, and of course the new filter cleans it up too.

 

And a word of advice if you're doing it yourself, it's not difficult, but when you undo the transmission sump bolts, leave the corners in place but unscrewed say a quarter of the way, so when the seal pops it won't totally bladder all over the place. Personal experience that is.

 

A large washing up bowl strategically positioned will be a good idea.

 

As the cars are quite sensitive souls,  and mine is a rather ungrateful sod, I personally wouldn't risk anything other than the Mopar fluid on this.

Edited February 8, 2020 by bignev