Anyone seen an clutch pack upgrade kit for the ZF 4HP22?

[Coyote_ar]

Anyone seen an clutch pack upgrade kit for the ZF 4HP22?

I know there's a company in the UK that upgrades 4HP22s with some 4HP24 parts, but they sell the full gearbox. And thats not what im looking for, i want to rebuild mine, but i would like to have some clutch packs able to hold a bit more torque.

AFAIK 4HP22 is good for at least 350nm, id like to be able to handle 400nm reliably.

Upgrading the gearbox cooling is a must for high torque applications? Im planning on adding a gearbox fluid temp sensor just to keep an eye on it. Anyone know whats the safe operating temperatures?

Also any other tip for upgrades that would allow to take on more torque without killing the trans, is really appreciated.

PS: no, i dont want a manual already got an e30 for that, i like my lazy old man gearbox :P

[shogun]

The 4HP22 can stand quite some power, officially 380 Nm. Last year we made a transmission fluid change and a valve body overhaul on a Maserati Biturbo with more power than the BMW using this trans and the 4hp22 was nice and clean and worked well.
Many cars use this trans https://en.wikipedia.org/wiki/ZF_4HP22_transmission

You might get some parts from the 4HP24 like the A-clutch, the housing is the same. That is what the U.K. company also does for the 4HP22 for the Landrover
differences between 4HP22(used on 735 and other BMW like the E30 models) and 4HP24 (used on E32 750)

There are numerous changes in the 24 , first off

Springs with different rates are incorporated, next the torque converter diameter is increased to 280 mm, then the bearing surface of the torque converter is longer to take the stronger loads, the converter lockup clutch diameter is increased to 300mm, the transmission bell housing is larger due to the increased converter size, the A transfer plate is 15 mm wider in order to accept the larger A clutch, the stator wheel shaft is now mounted with 6 countersunk screws for a tighter connection with the transfer plate, a new pump body was designed for the longer converter shaft bearing, the splines on the input shaft are longer, both sealing rings on the input shaft are cast iron, the A clutch has a larger diameter and the clutch friction surfaces are increased in size also, the number of plates in the B,C and D clutches was increased by one inch each,the one way clutch for 2nd gear has been stenghtened and riveted together, the oneway clutch for 3rd gear was changed from a roller type to a locking body type for greater torque, the planetary gear for 4 is much stronger now with forged webs, the output shaft diameter is increased and 2 holes are provided for more lubrication, the output flange has a larger bolt circle to take more force, the pan is deeper, the filter is different for the deeper pan.
Bell housing of the 4hp24 does not fit your car as well as the larger torque converter.
So basically you have to do a lot on the M30 engine to come to the limit of the normal 4HP22.

Trans fluid operating temperatures, the good and the bad:
How does heat affect transmission life?

TRANSMISSION FAILURE/TEMPERATURE CHART

Most automatic transmissions fail due to a breakdown of the transmission fluid (oil) caused by overheating. This chart provides a graphic display of heat's contribution to transmission failure.
http://www.txchange.com/heatchrt.htm


The question is what you are planning with the engine? Turbo? If not, the normal 4HP22 will just do find, 380 Nm is quite a number.

[Coyote_ar]

yeah, but i dont have access to a 24 here, very few of those, and most still attached to the car. so i wasnt looking into the hybrid 22-24 option.
but since this trans was used in many cars, many of those having big V8s and used for high torque applications like the land rovers, i thought maybe there was some kind of upgrade kit sold somewhere, maybe clutches with more bite or something like that.

as for the application, im planning a turbo M20B28. 350-380nm is good enough for what im looking for, thats M5 territory. but i want to be able to use that reliably, not fearing i will burn up the clutches every time i floor it.
I will be using a megasquirt ECU, with an electronic boost controller. So i could have different boost limits by gear. Maybe 1-2 have a lower boost to protect the trans in those shorter gears, then raise it for 3-4. Cause traction will be an issue on 1-2 anyway (have an open diff, so i wont be doing drag racing or anything crazy).

finally about the temp, so i guess using a dedicated oil cooler for the ATF would be a good idea to protect the trans under load. is there a minimum temp aswell, as in having a big oil cooler causing problems due to too cold ATF? i can always build some kind of electronic thermostat with an arduino, but i rather not.
ambient temps here are not that extreme, about -2c in winter to 38c in summer.

[632 Regal]

Not sure what the minimum temp would be but here is a chart:

http://myautomatictransmission.com/images/transmission_failure_chart.jpg

A trans builder I worked with long ago told me to always hook the aux cooler before it goes through the radiator, not after.

[Coyote_ar]

yeah, thats the same one shogun linked before. so im guessing that the cooler the trans fluid, the better.

from what i was able to find online, low temp is an issue at really low temps. the -2c we got here in winter are not really a problem. and even then after warming up the engine the trans fluid should be higher than that.

so keeping the trans fluid as cold as possible should be a good idea, no thermostat necesary.

[shogun]

In case you do not use a real power boost on the engine like turbo or something like that, I would suggest the normal 4HP22 will do for you. If you want to service it, service the valve body, and maybe a new A-clutch with new plates with enough "fat" on the metal parts, a master kit should do with all the friction parts http://www.makcotransmissionparts.com/ZF4HP22.html

For the E-clutch there is also something http://www.altousa.com/downloads/tech-drawings/12-110-BM341.pdf

[Coyote_ar]

i said im going to stick a turbo on the M20 stroked to 2.8. that can easily reach that torque. anyway my concern is that i can use it reliably. if with a full service with a master kit, plus an upgrade to the trans fluid cooling, its good enough then ill be happy with that.

[whiskychaser]

Sell the M20 and get a 540i?

[Coyote_ar]

why? the engine is not the problem. a turbo M20 can be more powerful than a NA v8 and gets better MPG when driving at legal speeds.
plus we got few 540i here ... and most are not that well maintained. They are more expensive to maintain in the first place, more powerful so people would drive em harder, and finally more expensive to buy (even if the car aint in that good shape).

it makes no sense to change the whole car just for a gearbox. specially if i can handle 380nm of torque with the one i got.
i like the M20, its a familiar engine to me and i know the ins and outs, very reliable when properly boosted. its the gearbox that its a new territory for me, so thats why im a bit lost there. been doing a lot of reading, but since its not a performance oriented gearbox, most people just ignore it aside from the basics.
initially when i bought the car i wasnt very fond of it, and planned to swap in a manual. but i started to like it, its not that bad if you dont intend to use it for a racetrack. the jump from 3rd to 4th is the only really bad thing, but you can fix that with boost. and on acceleration with a boosted engine an auto trans is even superior to a manual, since you wont lose boost while shifting.

[whiskychaser]

I was actually thinking of the 5HP30 auto in the 540i. That will take 560nm torque, is a 5 speed box and there isn't a leap from 3 to 4. You wouldn't need the turbo, Megasquirt, to go out to 2.8 or strengthen/rebuild the bottom end of a 20+ year old engine. I'm not trying to discourage you but point out another route to reliable power.

Maybe add your location/car to your sig?

[Coyote_ar]

cars are quite expensive here, and i happen to find my e34 really cheap cause it had lots of problems (mostly electrical and some worn out parts, fixed most of those in the past 6 months). thats why i got to buy it in the first place. the few 540i that we got here, are 3x times more expensive and usually not in great shape, since they are old cars that are expensive to maintain, most people just dont and use them till they break.
i payed 5k usd for my e34, and spent another 2k fixing it so far. a friend recently bought a 94 540i, he payed over 15k for the car and has spent almost 5k fixing it.

plus the reason i want to boost the M20, is because apart from already knowing the engine, its i already have most of the parts. i got forged rods and crank of a M52TUB28. Once i get the pistons ill have the crank machined down and balance the whole rotating assembly. i already have the megasquirt1 built for 3 coils + boost controller. i even have a set of M50 oil squirters to machine into the M20 block to have some extra cooling. refreshing the bottom end wont be the most expensive parts, its refreshing the head what will really cost a dime. but the difference between doing it this way, and buying a 540i is that this way i can do it little by little.
first ill focus on upgrading the bottom end since i already have most things for that. once i got the fully rebuilt bottom end stroked to 2.8 with the megasquirt. ill have a nice boost in power, something to enjoy while i get the parts to refresh the head.
i may do the boosting at the same time i rebuild the head, or do it after its installed. I already have a turbo ... technically its for the E30 track car im building ... but the E34 has been stealing E30 parts lately :P

so in the end, its really the trans thats the hard part for me. its been the focus of all the research i've been doing since i got the car, cause i never looked into it till i got it.

[632 Regal]

Now undersatanding what your looking for. give this thread a minute to figure it out, this is an international forum so when you post might be night time there with experience.

[Coyote_ar]

funny you mention that, since shogun is in japan, you are in US and whisky is in the UK. response time tends to be quite fast :)