Torque Converter Slipping -- SOLVED --

[benfbuilder]

If my trans really needs a rebuild, I am going to try and tackle it myself. I've got the space and the tools as well as being pretty mechanically inclined. My question is whether or not the torque converter is actually the issue. Could it be a valve body issue with a worn valve letting pressure through to the torque converter causing it to unlock and slip at high rpm? Could I use a 4.6 torque converter in my 4.4 if the torque converter is the root of the problem?

[RRPhil]

Originally Posted by benfbuilder

Could I use a 4.6 torque converter in my 4.4 if the torque converter is the root of the problem?

The 4.6is converter would not match the torque characteristics of your 4.4i engine and anyway it’s physically larger (280mm circuit diameter compared to 260mm) so the ribs in the bellhousing have to be machined to accommodate it.




The larger L51 converter was also used for the 4.8 litre Alpina B10 & Z8 Roadster models

Phil

[bcredliner]

The 5HP24 transmission is used in both the 4.4 and the 4.6. There is no part number for the bell housing portion for the transmission. What info do you have that indicates the torque convertor won't fit?

Assuming the 4.6 torque convertor fits there are lots of other specs particular to the application that enter into choosing the appropriate convertor for your needs. The following explains the complexity of that chore: https://www.youtube.com/watch?v=j5JFMs8gdbs

If it doesn't fit the option is out the window. If it does, you may or may not like how it changes the driving experience, assuming it is enough to notice. We would have to know the rpms that the 4.4 and 4.6 cams 'come on' to know if that matters but diff ratios are different, tire size is different etc.

IMO, based on the low frequency of 4.4 torque convertors failures, the stock convertor is all that you need in a stock 4.4 even if you are towing.

It is important to reiterate that at this point none of us know the cause of the problem you are having and IMO taking it to a 'certified' well recommended transmission shop familiar with BMW transmissions before spending a dime on new parts or tearing it down is the best course of action. If I were to spend any $$$ it would be to drain the fluid and remove the pan so you can see if there is metal in the pan, examine the fluid, replace the filter and fluid to see if there is improvement. Quite often, once there is a transmission problem changing fluid will at best be a short term benefit but if is worth a try.

Be sure to make an informed decision before you decide to pull and repair an automatic transmission, it's not for the faint hearted.

[RRPhil]

There are three bellhousings used for the 15 different models of the 5HP24 used in BMWs

1) 1058 322 016 is used for the majority of models (003, 004, 005, 010, 016, 017, 018, 020, 021, 022 & 029)
2) 1058 322 012 is used for the diesel models (023 & 036) – obviously because they’re mated to the M57 engine rather than the M62
3) 1058 322 020 is used for the 034 & 035 models which use the larger L51 torque converter. The casting is the same as for 1058 322 016 but, as already discussed, the stiffening ribs are partially machined away to provide clearance for the larger converter

Nine different torque converters are used for BMW models of the 5HP24 (and 4 different converters for Jaguar models)

Phil

[bcredliner]

Good to know. Do you have a link to that information Phil?

[jcp240z]

If you don't know, Phil has pretty much written the book on tear down and rebuild of the 5HP24 transmission. You'll find his great knowledge on a number of groups which use such it such as BMW, Range Rover and if I recall correctly Jaguar. I think he rebuilds them as a hobby��

[X53Jay4.8is]

Originally Posted by jcp240z

If you don't know, Phil has pretty much written the book on tear down and rebuild of the 5HP24 transmission. You'll find his great knowledge on a number of groups which use such it such as BMW, Range Rover and if I recall correctly Jaguar. I think he rebuilds them as a hobby��

Yes a man of Phil's talents does not go unrecognized. He is a wealth of a resource.

[RRPhil]

Originally Posted by bcredliner

Do you have a link to that information Phil?

I use ZF’s Service Data Management software which covers all of the models, although this pdf version is fine for just North American models :

https://www.zf.com/global/media/zf_m...sa_4/5HP24.pdf

and the repair manual is useful too :

http://www.jagrepair.com/images/Auto...r%20Manual.pdf

I’ve got quite a few 5HP24s on the go at the moment :



Phil

[X53Jay4.8is]

Originally Posted by RRPhil

I use ZF’s Service Data Management software which covers all of the models, although this pdf version is fine for just North American models :

https://www.zf.com/global/media/zf_m...sa_4/5HP24.pdf

and the repair manual is useful too :

http://www.jagrepair.com/images/Auto...r%20Manual.pdf

I’ve got quite a few 5HP24s on the go at the moment :



Phil

Wow Phil is like a God. A restorer of what was once broken (5HP24trans) and now healed.

[bcredliner]

Thanks for the links.

Nothing like the security of lots of backlog. Nice looking space and well organized. Says a lot.

Do you do high performance rebuilds for faster shifts, to handle more torque, etc? Can the 24 be replaced with a ZF with more gears without extensive modifications?