5hp18 -> 5hp30

[Frank87]

Hello,

After overhauling a 5HP18 and doing some more neat modifications on the car, it's time to go for some bigger projects. In the future I will want to fit a BMW 4.0 V8 or 4.4 V8. The 5HP18 has a factory limit of 310Nm. It can just barely take a 3.0 V8.

The 4.0 was always delivered with a 5HP30 gearbox (560Nm max.) and the 4.4 was delivered with a 5HP30 in the first year before the intermediate 5HP24 (440 max.) was released.

A 5HP30 will be a direct fit into my car and a 4.0 transmission mount + drive-shaft will take care of the rest. Fitting a 5HP30 basically finishes the transmission-to-wheels part of a bigger engine swap and will give me a 560Nm box to handle a "little" 300Nm engine.

Since the 5HP18 and 5HP30 are both fully electronic, I will need to do some electrical work aswell. The 5HP30 EGS/AGS module is identical to the 5HP18 module regarding size, shape and pin layout. The wiring down to the transmission is different as the 5HP30 has a totally different valvebody. The BMW Wiring Diagram System already showed me how I will have to change certain wires at certain connectors to ensure the proper signals are transferred back and forth. I foresee no real problem here.

The car is not equipped with the anti-theft mechanism where EGS/AGS and DME have to be linked software-wise. So far, so good. I think I have this transmission swap properly on paper.

The problem that I can not fix however, is that the 5HP30 will have to apply shift times and shift pressures based on the torque/RPM curve of my 3.0 V8. The EGS/AGS will be programmed to shift based ona 4.0 torque/RPM curve.

Reason why I think this is a problem, is that if I would simply hook up the 5HP30, assuming all wires have been rewired correctly, it will time its shifts and pressures based on the throttle body sensor position and the Nm it expects to receive from a 4.0. Since it will receive far less Nm from a 3.0, it will possibly apply too much pressure.

Can anyone tell me if the data for the load profile is stored on the EPROM in the EGS/AGS? If so, I would have to load the engine load data of the 3.0 onto the 5HP30 EPROM so that it's shifting and solenoid actuation is the same as with a 4.0 but now based on a 3.0 load profile.

Can anyone with DME/DDE chiptuning or mapping in general tell me what these programmed variables look like?

Hope to hear from you guys. Once I start working on a 5HP30, the pictures and videos will be online.

[632 Regal]

Can't help with tuning or mapping but you will need the large differential, output shafts and rear wheel setups unless you cut the driveshaft to work with the mid size diff.

When I was looking into this swap it came down to popping in a manual 5 or 6 speed instead of the giant torque eating 5hp-30. Same driveshaft as for the 5hp-18.

[Frank87]

Yes, ultimately I will need to work on the rear end of the driveline aswell. For now I just want to have the 5HP30 working with my small engine. In the future I will do the rear end the way I want to. I will choose the diff internals that I want and fit them in a large house, with the large shafts with a 4.0 drive shaft. For now however, I focus 100% on the transmission itself.

If a 5HP30 -> 3.0 will simply not work not even with some $$$, I will either beef up the 5HP18 and build a M60B35 based on M62 parts (just for the fun of it) or go directly 4.0+trans+shaft+diff+shafts.

[whiskychaser]

The TCM is going to monitor throttle position and load. I imagine that if it concludes it has a low powered 4.0 litre up front, it will just hang onto gears. I can't help with the mapping . But I think I may know a man who probably can. Owner is a member of a BMW forum and really does know his stuff. Maybe give them a try?:

http://www.endtuning.com/

[Frank87]

Hello guys!

It has been a while since I posted here. Some of you have read my thread on the 5HP18 autobox stuff as I overhauled one in 2016. That box is still doing fine, no issues at all.

I am in the process of completely stripping and doing full body restauration on the E34 fitted with that box. I am talking full restauration of the exterior and powder coating the front and rear subframe, overhauled diff etc.. etc...

Since someday I will want a bigger engine, 4.0 or "M60 4.4" custom engine, I will need a stronger gearbox. I will fit a 5HP30 somewhere in 2019 after full body restauration has been done. Naturally, this box will also be completely overhauled.

I will tell you guys globally how this setup will work. This is good info for anyone who has the intention to swap to a different autobox.

1 - Fitment
Generally, since the M60 3.0 and M60 4.0 have the same bolt pattern, the box + converter will fit right away. I will need the original gearbox support piece for the E34 5HP30 but that is easy to find on yards. Fitting the box behind the engine is a matter of wrenching. Now, the 4.0 uses the large case differential and the 5HP30 is longer in length compared to the 5HP18. In sum, I will need an original 540i diff (or at least the large housing) and a shorter driveshaft / original 540i driveshaft. I have that sourced and those items are coming in. Note that the large diff housing uses different shafts to connect to the wheel hubs. The diameter is bigger and they have more bolt holes.

2 - Electronics
The early EGS should fit without any theft system problem. The 5HP18 and 5HP30 chip casing and pin construction is the same which means it will slot right in. HOWEVER, the PIN LAYOUT and the CONNECTOR TO THE GEARBOX is different. I will need an ORIGINAL 540i or 740i cable piece from box to EGS electric box. I will also have to use the electrical documentation to rewire some wires. Not much of a challenge just need to make a clear guide for myself.

3 - Driveability
These electronic gearboxes work on a shift program based on which the EGS sends signals to the solenoids engaging / disengaging the right clutches at the right time. I always thought that the gearbox computer needed to know the exact engine torque / rpm curve to know exactly what it will handle in torque when shifting. On the most modern gearboxes, this is possibly true as these gearboxes have full modular solenoids. However, the 5HP18 and 5HP30 are some sort of a bridge between old school transmission hydraulics, pressure + governor and modern fully modular solenoid shifting gearboxes. Basically, the 5HP18 and 5HP30 need to know the engine load for its shift program. In the past, this was measured with a vacuum line to the engine block and a vacuum modulator on the gearbox housing. Depending on the pressure in the engine block, the gearbox shifts or does not shift based on valves actuated by that pressure. On the 5HP18 and 5HP30, this is no longer directly done with modulator pressure but with electronics. Using the intake manifold pressure sensor, the gearbox computer knows the pressure and engine load. Depending on:
- That engine load
- How far the throttle valve is open
- How much RPM the car is doing
- And some other variables (cornering, temperatures)
The 5HP18 / 5HP30 decides to upshift or downshift.

I was wrong in thinking the 5HP18 and 5HP30 need to know the exact torque / rpm curve thinking engine load was used to decide HOW to shift (sooner / later & more or less pressure). I found out this is not the case. They do not use engine load to decide WHEN and HOW to shift but only WHEN to shift.

So basically, between the old non-electronic boxes and the modern boxes with full modular solenoid action, is the 5HP18 and 5HP30.

This all being said, I think that after fitting all the 540i parts and the 5HP30.. also rewiring the stuff, I should have a perfectly fine shifting 5HP30 behind my M60B30 "little" engine.

The main advantage is that my car is "large V8 ready". Another advantage is that the M60B30 will put only 290Nm on a box made to handle 560Nm.

I will keep you guys updated.

[Frank87]

Oops sorry, didnt update this but started a new thread. Read latest update here: http://www.bimmernut.com/forum/showt...30-on-a-3-0-V8

[shogun]

no problem, I merged the 2 threads to one.

[Frank87]

Allright I made some progress here. I scored a 5HP30, shaft, differential and I got a 4.0 wiring loom incoming.

This means I have everything I need for a direct swap to a 5HP30. I will overhaul this gearbox first. This will not be a regular overhaul. Here is what I have been reading on lately:

The box was market ready in 1991 and rated for 560Nm. At that moment, the only candidate was the BMW 4.0 liter engine doing 400Nm. Later, the BMW 5.4 V12, Aston Martin V12, Bentley V8 and Rolls (BMWV12) were equipped with this box. There is a clear difference between a V8 and a V12 box. The housing is just about identical but the V12 box uses DIFFERENT clutch plates and DIFFERENT quantities of clutch plates.

Heres the numbers:
- 4.0 has 5 - 3 - 4 - 5 - 5 - 5 - 6 fiber clutch plates
- V12 models have 5 - 3 - 3 - 6 - 5 - 6 - 6 fiber clutch plates

The part numbers of these clutch plates are different but their dimensions are identical.

I think they added more clutch material to handle the power of these engines. The Aston Martin V12 does 560+Nm stock. It would not surprise me if a V12 version of the 5HP30 can handle close to 600Nm. Now, the interesting part is, can I fit these V12 5HP30 parts into my V8 5HP30 and boost clutch size + clutch plate type? I think I can.

What I will do, is score a V12 5HP30, use this drivetrain into my 5HP30. I will take 1 drum from the 4.0 version as it can hold more clutch material than the V12 version. Hoping this will fit. I will also use the clutch plates that are meant for the V12 engines.

[632 Regal]

If you remove the wavy plates and substitute them for the steel plates you should get a more positive shift. But you will feel the gear changes and less chance of slippage during shifts. The clearance within .100 wont matter much at all, I prefer .080 tho, I use .100 as max clearance.

[Frank87]

You are right, removing those thin plates will give me a more direct shift and MAY give me an opportunity to add more clutch material.

However, those plates give the box a smooth clutch application and also smooth shift feeling. Since I want this car to be daily driveable and also on long holiday trips, I will keep those plates in.

Since the car will never have a bigger engine than a M60 + 4.4 parts (440Nm +/-), the 560+Nm Torque capacity is more than enough. I would not need to do anything for that.

Depending on what I see when opening the box and the room each clutch pack has, I decide how to progress. The idea is the following:
- Make sure the box can really handle the 560Nm (and probably more) with V12 box parts
- Improve the capacity by any reasonable means which do not sacrifice any other aspect of driveability or shift behaviour

Long term project so we will see.