cheongthong · Sep 16, 2012

hi ,

will emissions testing destroy the 4 hp22 auto transmission if the engine is on high idle 2500 rpm

.

wammers · Sep 16, 2012

Emissions test should be done as quickly as possible not using any more throttle than is needed. No more than 50% of full speed for a short time. Over revving any automatic with the gear box in park or neutral for any length of time can damage the gearbox.

Saint.V8 · Sep 16, 2012

Shouldn't think so as the Gearbox should be in park or neutral surely and as such no drive is being taken by the 'box...!!

Maybe someone will correct me!

Saint.V8 · Sep 16, 2012

wammers said:
Emissions test should be done as quickly as possible not using any more throttle than is needed. No more than 50% of full speed for a short time. Over revving any automatic with the gear box in park or neutral for any length of time can damage the gearbox.

And I have been corrected

cheongthong · Sep 16, 2012

normally if you go for a mot emission testing first ; the mechanic will push the gas pedal hard down to the floor , this will kill the transmission ,

StuckAgainSteve · Sep 17, 2012

cheongthong said:
hi , will emissions testing destroy the 4 hp22 auto transmission if the engine is on high idle 2500 rpm .

The common fault which often destroyed 4hp22 clutch packs if revved in neutral or park after the transmissions had been in gear was fixed by the time the P38 came along. The front clutch pack's pressure failed to bleed down and would be torn to shreds by revving in park or neutral. To be safe with automatic transmissions, the engine should always be switched off for 30 seconds to allow the fluid pressure to dissipate completely, then restarted and left in park.

cheongthong · Sep 17, 2012

the first p38 box still have that problem 95...96 versie ?

StuckAgainSteve · Sep 17, 2012

cheongthong said:
the first p38 box still have that problem 95...96 versie ?

As I said originally, as far as I know the 4HP22 bleed-down problems were sorted before the P38 was released.

Saint.V8 · Sep 17, 2012

StuckAgainSteve said:
As I said originally, as far as I know the 4HP22 bleed-down problems were sorted before the P38 was released.

I read somewhere thata tech bulletin was released in 1991 that mentioned that, and that is was to be sorted...

qwertz · Sep 18, 2012

There was a tech bulletin in 1991, it explained the problem and recommended to turn off the engine for 30 sec to bleed pressure off, start again and perform emission test with high RPM.

It is in here:
Caveats about the ZF automatic transmission!
bigcoupe.com :: View topic - Caveats about the ZF automatic transmission

This info:
Transmission Diagnosis & Repair

says 4HP22 in P38 is affected (read "Rebuld/replacemnt options").

I saw no reliable information that it was fixed.

cheongthong · Sep 18, 2012

i think the problem still exit ;; the p38 4hp22 transmission is not fix, i have never known that i have turn the engine OFF for 30 second ,, thank ,

jamesmartin · Sep 18, 2012

does it ?i aint seen it ,its only diesel boxes that take clutches out usually

cheongthong · Sep 19, 2012

it nothing to do with the diesel engine ; 4hp22 is also fix on the petrol engine ,,,,

jamesmartin · Sep 19, 2012

same clutches

cheongthong

Active Member

wammers

No longer with us, RIP

Saint.V8

Dyed-in-the-wool 100% RR Junkie

Saint.V8

Dyed-in-the-wool 100% RR Junkie

cheongthong

Active Member

StuckAgainSteve

Well-Known Member

cheongthong

Active Member

StuckAgainSteve

Well-Known Member

Saint.V8

Dyed-in-the-wool 100% RR Junkie

qwertz

Member

cheongthong

Active Member

jamesmartin

Well-Known Member

cheongthong

Active Member

jamesmartin

Well-Known Member

Similar threads