ZF-HP22 auto gearbox slipping

[volvo B230ET]

I have a 1988 Volvo 760 turbo and when were going down the motorway at 80mph in 4th gear the car revs quite high at 3000 rpm now I don't think it should be doing that. I know that automatic transmissions are supposed to slip but this is a bit to much. I've checked the oil and I doesn't smell burnt. but id like to know what's causing this to happen and what can I do to fix this.

[spesmea]

Hallo
I would consider the state of the transmission oil IE:when was it last
changed & the transmission oil filter changed?? Normally this is the answer
to your problem.There could also be a problem with the torque converter but
this would be unusual.
Regards
Bill

[rogerthechorister]

I think those revs are about right. I'll take mine (identical spec) out for a spin later and tell you what my revs at 80mph are.

[Jonathan_angelo]

Originally Posted by volvo B230ET

I have a 1988 Volvo 760 turbo and when were going down the motorway at 80mph in 4th gear the car revs quite high at 3000 rpm now I don't think it should be doing that. I know that automatic transmissions are supposed to slip but this is a bit to much. I've checked the oil and I doesn't smell burnt. but id like to know what's causing this to happen and what can I do to fix this.

It's perfectly normal. I had a 1989 764 Turbo in green, many, many years ago and it was a high rever. Gear box was fine, no slipping. The gearing is a bit lower than would be acceptable in today's market.
I can't remember if ther have an overdrive facility but im sure its a 4speed unit on those?

[Jonathan_angelo]

Please find attached a pic of my old 764 Turbo. Cost me £500 back in 2004 and I loved it.

[Alasdair1]

I had a 940s auto J reg and it revved high as well. I always felt it could do with an extra gear. I managed to get it to drop by 150rpm at around the 70mph mark by changing the transmission fluid.

Alasdair

[rogerthechorister]

Checked. My 760T does exactly 3,000 rpm at exactly 80 mph.

[volvo B230ET]

my auto gearbox (ZF HP-22) is due for a oil change and the oil grade is Dexron 2 D. can I use Dexron 3 instead because ive heard that dex 2 has rusting properties and dex 3 doesn't. what would you suggest is better and why. and do you think it a good idea to change my rear axle oil while im at it because its never been changed and the cars done 216,050 miles.




image is from my old Volvo because I had two exactly the same (760 turbo) and I took the old one apart a spears for the new one