Some ZF 4HP22 questions...

[auto660]

I've been doing some research on the ZF 4HP22/24 transmissions and information seems to be scarce on them. This forum seems to be one of the few places where people have actually been swapping and modifying them so i'm hoping some members here can help me out for a bit. 

I'm currently driving a Volvo 240 with a turbo conversion for which i'm searching a nice automatic trans setup. This pointed me towards the ZF 4HP22 transmission that came in the later Volvo 740's and fits relatively easily in the 240, albeit with some minor mods. The 4HP22 isn't strong enough though from what i've read, especially the early full hydraulic boxes. But the bellhousing and tailhousing are said to be swappable between the different 4HP22/24 variations, which gives some room for mixing and matching of parts. The car is already running a MS3 ECU so it would be even greater if the trans could be controlled electronically via the Megasquirt trans control system.

TL;DR

So my question is... Can the Volvo 4HP22 bellhousing and tailhousing be swapped over to an electronically controlled 4HP24? The Volvo comes with an 11" torque converter, that should fit the 4HP24 right? This would make for a relatively cheap automatic transmission swap that's quite tough and controllable with the Megasquirt system. 

[Daan]

Hi and welcome to the forum. Volvo is obviously not our thing, however, there is a lot of info on the Ashcroft website:

https://ashcroft-transmissions.co.uk/product/zf4hp22eh/

Regards,

Daan

[Bowie69]

As I understand it, yes, the bellhousing are swappable. 

In fact, you can interchange a lot of the later electronic boxes internal parts to strengthen the HP22, but still end up with a hydraulically controlled box, if that's what you want. 

The HP24 can be controlled with Megashift, but I'm not an expert on MS3, for all I know it may have trans control built in now. The shift solenoids are the same as, I think, the 4L60E, but do some research, there's only so many ways you can't turn on and off two solenoids! 

 

[auto660]

1 minute ago, Bowie69 said:

As I understand it, yes, the bellhousing are swappable. 

In fact, you can interchange a lot of the later electronic boxes internal parts to strengthen the HP22, but still end up with a hydraulically controlled box, if that's what you want. 

The HP24 can be controlled with Megashift, but I'm not an expert on MS3, for all I know it may have trans control built in now. The shift solenoids are the same as, I think, the 4L60E, but do some research, there's only so many ways you can't turn on and off two solenoids! 

 

That sounds good, it would be nice if i could use the electronic box. That would give me the option to finetune the trans behaviour to my liking and have stuff like paddle shifters.

The megashift firmware is now replaced by the new "Microsquirt Transmission Control" firmware by the way, which can also run on their CANBUS GPIO extender box. Making it quite an attractive option at just €300.  The latest version got support for the 4HP24 transmission so it should work just fine. The MS3 itself doesn't have any trans control options on it's own unfortunately.

[smallfry]

You can swap the bellhousing and you can swap the tailshaft housing. BUT the Land Rover versions of the 4HP24 are all for use with a transfer box for the 4WD bolted to it, so to use one, you will need to strip the box and change the tailshaft itself as well. Jaguar versions will have a RWD tailshaft and housing, and possibly BMW. The rear mounting arrangement may be different, but you could just swap the housing. The other thing is most of these tailshaft housings have no provision for a speedometer output. I am not familiar with Volvo so do not know how that works

Also, the earlier Range Rover 4HP24 has a different input shaft to suit a bigger torque converter which will probably not fit in the Volvo bellhousing. You would have to physically try it. The later gearbox has a smaller shaft, which will be the same as your Volvo one.

I know nothing about electronics, so cannot help with that aspect. 

[Bowie69]

50 minutes ago, auto660 said:

That sounds good, it would be nice if i could use the electronic box. That would give me the option to finetune the trans behaviour to my liking and have stuff like paddle shifters.

The megashift firmware is now replaced by the new "Microsquirt Transmission Control" firmware by the way, which can also run on their CANBUS GPIO extender box. Making it quite an attractive option at just €300.  The latest version got support for the 4HP24 transmission so it should work just fine. The MS3 itself doesn't have any trans control options on it's own unfortunately.

That's good to know re:microsquirt TCU, I knew they used that hardware, wasn't sure what had happened, since, it always felt quite an expensive route, but if it now runs on the GPIO extender then definitely the way to go. 

[auto660]

16 minutes ago, smallfry said:

You can swap the bellhousing and you can swap the tailshaft housing. BUT the Land Rover versions of the 4HP24 are all for use with a transfer box for the 4WD bolted to it, so to use one, you will need to strip the box and change the tailshaft itself as well. Jaguar versions will have a RWD tailshaft and housing, and possibly BMW. The rear mounting arrangement may be different, but you could just swap the housing. The other thing is most of these tailshaft housings have no provision for a speedometer output. I am not familiar with Volvo so do not know how that works

Also, the earlier Range Rover 4HP24 has a different input shaft to suit a bigger torque converter which will probably not fit in the Volvo bellhousing. You would have to physically try it. The later gearbox has a smaller shaft, which will be the same as your Volvo one.

I know nothing about electronics, so cannot help with that aspect. 

I'll probably do a rebuild anyway to start with a fresh transmission, so having to change the tailshaft shouldn't be that much additional work. As long as it actually fits together. Regarding the input shaft diameter, it would probably be wise to first buy the Volvo transmission and measure the shaft diameter before buying the 4HP24 i think, something to keep track of. The speedometer output won't be problem luckily, it's got an electric sensor in the rear differential for that, making things a lot easier. The later 4HP24 gearbox is also shorter than the earlier one, right? Making it the same size as the 22.

The engine (2.3L) currently makes about 280HP and 420NM, with future plans for a slight increase to 330~350HP and 450~470NM with a turbo upgrade. Would the 4HP24 be capable of managing these power levels?

Edited August 13, 2023 by auto660

[Bowie69]

You'll need to consider the torque converter, the larger ones will normally have a lower stall speed, not something you will likely want with a revvy over boosted 2.3l engine. 

[elbekko]

Controlling the 4HP24E shouldn't be an issue, I've been considering doing the same with a Haltech. As Bowie said, it's just a few solenoids, IIRC line pressure and such is all regulated internally.

[smallfry]

The 4HP24 is LONGER than the 22 by about 15mm. The input shafts can be longer.

4HP24 is rated to 450 nm. I do not know if or how it can be uprated from there. It would probably need  more plates and increased pressures, but I don't know know if it can be done with these, like it can with American boxes.

Might be better off going for a 6HP26 with an adaptor plate. Much stronger, cheaper to buy and would not need uprating.  

[auto660]

@Bowie69That's indeed an important aspect, especially with a turbo engine. I've been looking for the torque converter stall speed of the Volvo 4HP22 and it seems like they used different stall speeds for different engine models. The non-turbo engine (B230E) came with a 2150RPM stall speed converter which would be a tad on the low side. The turbo engine (B230ET) came with a converter that's rated at 2000/2450, which would suit the engine quite well i think. The engine has been built in such way that it has a wide powerband and should be fine with a (lazy) automatic. It's got a ported cylinder head combined with a stock cam (~212in/ex) so it still makes some nice low-down torque, it just carries on a bit further into the rev range now. The small turbo starts giving positive pressure from ~1500RPM and the turbo gauge is pegged from about ~2700RPM onwards, which is about ~1.2bar of boost pressure.  Peak power is 280, but it's got 260+ all the way from 4800 till about 6700, it kinda drives like rev-happy turbodiesel currently. 

 

@elbekko From what i've seen the trans got solenoids for regulating the shifts, but it also got an additional solenoid for the line pressure regulation and one for the lock-up it seems.

 

@smallfry Using a 6HP26 or an 8HP70 would be the best way to do this, but i can't find any adapter kits for mating one to the Volvo B230 engine. The megasquirt trans control firmware doesn't support them either and i'm not sure they fit the Volvo 240 trans tunnel. The nice thing about the 4HP24 would be that it's relatively plug&play with the stuff i'm already using, and that's helps a lot when doing this kinda stuff on a student budget. 

 

Does anybody know the ZF model numbers for the (later) small shaft versions of the 4HP24? I've found that the 065 model from a (Land) Rover should have the small input shaft but they are a bit rare and expensive here. There are a lot of Jaguar transmissions though. Currently eyeballing a 059 model from a '95 Jaguar XJ6 (X300 4.0 24V) but i'm not sure if that one got the small shaft. Can't really find any further info on that.

RR Auto Box ZF4 HP22 pt2.pdf

[elbekko]

4 hours ago, auto660 said:

@elbekko From what i've seen the trans got solenoids for regulating the shifts, but it also got an additional solenoid for the line pressure regulation and one for the lock-up it seems.

Ah, no, you're right. It just defaults to full pressure, and can be modulated from there.

Excerpt from the Range Rover RAVE manual about the operation and pinout of the box attached.

4hp24e operation.pdf

[landroversforever]

Not to want to push anyone away from here to other places.... but have you tried the Turbobricks forum? Not been on there for a long time, but might be worth a look. 

[smallfry]

The only LR one that will be any good to you is the 065. There is another one, a 005, but I cant remember what it fits, and I have only ever seen one.

I dont know about the Jag ones, I only have 4HP22s from them, and a couple of BMW ones, so I cant help you with numbers.  TBH I think you would be better off with a Jag one, and swap the bellhousing. From what I can remember they have the input shaft you need. They have the right tailshaft, but the rear mount is offset to one side, so you could sway the housing for your Volvo one, or BMW which I think is the same.

Jag engines are quite torquey, so may have better internals.

I know what you mean about budget, thats why I will stick with the 4HP boxes 

[auto660]

4 hours ago, landroversforever said:

Not to want to push anyone away from here to other places.... but have you tried the Turbobricks forum? Not been on there for a long time, but might be worth a look. 

I'm familiar with Turbobricks, great forum for old Volvo stuff. It's just that these ZF boxen aren't that familiar there because they haven't been used that much on USA Volvo's. Most people swap to either AW or manual boxes because of parts availability or simply regarding the ZF as unreliable because of the park/neutral revving thingy. So this seemed like a more appropriate place, even if it's not for Volvo's.

2 hours ago, smallfry said:

The only LR one that will be any good to you is the 065. There is another one, a 005, but I cant remember what it fits, and I have only ever seen one.

I dont know about the Jag ones, I only have 4HP22s from them, and a couple of BMW ones, so I cant help you with numbers.  TBH I think you would be better off with a Jag one, and swap the bellhousing. From what I can remember they have the input shaft you need. They have the right tailshaft, but the rear mount is offset to one side, so you could sway the housing for your Volvo one, or BMW which I think is the same.

Jag engines are quite torquey, so may have better internals.

I know what you mean about budget, thats why I will stick with the 4HP boxes 

Hmm, seems like i've got to dig further into the Jag stuff. It could be that BMW and Volvo use the same output shaft, the guibo/flex disc at the driveshaft flange is interchangeable between them on the manual boxes at least.

[smallfry]

All the Jag ones I have seen have a proper flange on the output shaft. 

[auto660]

Just picked up a 4HP24 from a Jaaggggg for cheap, it's coded 1043-030-059. The torque converter measures about 300mm (11,75") in diameter, would that be the medium one (with the smaller shaft) or the large one (with the larger shaft)?

Edited August 16, 2023 by auto660

[smallfry]

2 hours ago, auto660 said:

Just picked up a 4HP24 from a Jaaggggg for cheap, it's coded 1043-030-059. The torque converter measures about 300mm (11,75") in diameter, would that be the medium one (with the smaller shaft) or the large one (with the larger shaft)?

Thats the medium size one. There are many specs though. Physical difference will be the mounting points and the boss that fits into the end of the crankshaft.

[auto660]

15 hours ago, smallfry said:

Thats the medium size one. There are many specs though. Physical difference will be the mounting points and the boss that fits into the end of the crankshaft.

Yeah i probably won't be using the Jag torque converter, but since the input shaft is different for the large TC it still seemed important which type it is. The medium one should be interchangeable with the Volvo torque converter from what i've understood so that would be nice. Now i've gotta find a Volvo ZF box for reasonable money... Will keep you guys updated on this. 

[JohnnoK]

On 8/17/2023 at 4:43 PM, auto660 said:

Yeah i probably won't be using the Jag torque converter, but since the input shaft is different for the large TC it still seemed important which type it is. The medium one should be interchangeable with the Volvo torque converter from what i've understood so that would be nice. Now i've gotta find a Volvo ZF box for reasonable money... Will keep you guys updated on this. 

For what I understand, in the Land Rovers the different TCs all fit any 4HP box, the difference being the TC to bell-housing fit that blocks the P38 TC being used for the Defender/Disco boxes due to its diameter.

[Carloz]

I have a Jaguar 4.0 24V 4HP24EH (electronic) auto box in my garage and a RRC 3.9 4HP22 hydraulic.

About everything is swappable: hydraulic 4HP22 casing to 4HP24 internals for example.

Most clear difference is the pump body between bellhousing and gearbox which is about 20mm longer(bigger) on the 4HP24