auto box problem

english111 · Oct 15, 2009

my rr will drive if i go into 1st 2nd and 3rd then in drive it will then go up and down without problems unless i slow to below 10mph but if i go stright into drive it just revs any one have any ideas
thanks

Bemble · Oct 15, 2009

Sounds like a transmission that uses a sprag (one-way clutch) to react 1st gear but has a by-pass clutch for overrun braking when you select it 'manually'. The sprag is knackered so the engine just revs like it's in neutral when you select 'D' but when you select '1' the clutch engages and overrides the sprag.
What model is it?

english111 · Oct 15, 2009

sorry not sure what model it is are there any tel tel signs on the box in situ

fett · Oct 15, 2009

Have a look under FAQS on the Ashcroft transmissions websites, I have become well aquainted with it since trouble with my auto.

Bemble · Oct 15, 2009

english111 said:
sorry not sure what model it is are there any tel tel signs on the box in situ

Sorry, I meant your Range Rover. Is it a Classic, P38 or L322? Petrol or Diesel?

english111 · Oct 16, 2009

ok it is a 1997 p38 diesel had a look on Ashcroft transmissions websites they say get a new one they are probably right but i can hope its only a silly thing like filter and oil as it is ok once it is going

njh2 · Oct 16, 2009

I replaced the part and had many, many miles of trouble free motoring.....thought someone had dropped a tank next to me when it went though...pulling of at the t-lights....blimey!

Bemble · Oct 17, 2009

Yes, sure enough, the 4HP22 does use a sprag clutch to react 1st gear in 'D' - numbered 15 in the diagram attached. Clutch 8 bypasses it when you engage '1'.
I shouldn't waste money on changing fluid & filters if I were you - your transmission needs a rebuild.

english111 · Oct 30, 2009

is there any differance between a gearbox fitted to a 4.6 and a gearbox fitted to a bmw engine

nathan5346 · Oct 30, 2009

yep, ones a 4.6 box and the others a 2.5 box

Bemble · Oct 30, 2009

The diesel & 4.0 petrol use the ZF 4HP22 transmission, the 4.6 uses the higher capacity ZF 4HP24. Petrol models have a larger torque converter than the diesel.

Datatek · Oct 30, 2009

Bemble said:
The diesel & 4.0 petrol use the ZF 4HP22 transmission, the 4.6 uses the higher capacity ZF 4HP24. Petrol models have a larger torque converter than the diesel.

According to RAVE, the 4HP24 box is slightly longer than the 4HP22

auto box problem

english111

Active Member

Bemble

Well-Known Member

english111

Active Member

fett

Well-Known Member

Bemble

Well-Known Member

english111

Active Member

njh2

Active Member

Bemble

Well-Known Member

Attachments

english111

Active Member

nathan5346

Well-Known Member

Bemble

Well-Known Member

Datatek

Well-Known Member

Similar threads