Popular Post Tobias Posted February 21, 2023 Popular Post Share Posted February 21, 2023 Hi, I have started the long overdue mating of HP22 and HP24 parts. The purpose is to have a sturdy autobox for the 2.8 300tdi that will power the Pulse ambulance we are building. I start with the core of a 300tdi 1997 Discovery 1 autobox, ZF4HP22 Then I will pull front cover, oil pump, toque converter and "the internal bits" from an early RR P38 4.6 box, as has been vaguely described by Ashcroft and others over the years. I will use a conversion kit from M&D Engineering to mate the front cover to the 300tdi block. The 300tdi is bored and will get pistons, conrods and crank to make it into a 2.8, with tweaking of the injection pump I expect good oompf for steep hills in Norway and towing. Both boxes are torn down and the putting of internals into the box has started, but it is a pain to align everything and not drop something to have to start over, still not there... I add some pictures. Please add comments, questions and hints. 6 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted February 21, 2023 Share Posted February 21, 2023 I think you'll have most people running for the hills at this point.... Good luck with the build, following..... Quote Link to comment Share on other sites More sharing options...
Gazzar Posted February 21, 2023 Share Posted February 21, 2023 Ooh, gearbox thread! More photos!! Quote Link to comment Share on other sites More sharing options...
Tobias Posted February 21, 2023 Author Share Posted February 21, 2023 6 hours ago, Gazzar said: Ooh, gearbox thread! More photos!! Anything in particular you’d like photos of, Gazzar? Quote Link to comment Share on other sites More sharing options...
Gazzar Posted February 21, 2023 Share Posted February 21, 2023 No! The whole thing. I've never tackled an auto, so curious and fascinated. Quote Link to comment Share on other sites More sharing options...
hurbie Posted February 21, 2023 Share Posted February 21, 2023 yes , interesting to follow ! Quote Link to comment Share on other sites More sharing options...
Wytze Posted February 21, 2023 Share Posted February 21, 2023 7 hours ago, Tobias said: Hi, I have started the long overdue mating of HP22 and HP24 parts. The purpose is to have a sturdy autobox for the 2.8 300tdi that will power the Pulse ambulance we are building. I start with the core of a 300tdi 1997 Discovery 1 autobox, ZF4HP22 Then I will pull front cover, oil pump, toque converter and "the internal bits" from an early RR P38 4.6 box, as has been vaguely described by Ashcroft and others over the years. I will use a conversion kit from M&D Engineering to mate the front cover to the 300tdi block. The 300tdi is bored and will get pistons, conrods and crank to make it into a 2.8, with tweaking of the injection pump I expect good oompf for steep hills in Norway and towing. Both boxes are torn down and the putting of internals into the box has started, but it is a pain to align everything and not drop something to have to start over, still not there... I add some pictures. Please add comments, questions and hints. Oh yes! I'm planning on doing the same. Following with interest. Keep that coming, very nice! Quote Link to comment Share on other sites More sharing options...
Arjan Posted February 21, 2023 Share Posted February 21, 2023 Very interesting ! You, Sir, have serious b.ll. to take those boxes on... Quote Link to comment Share on other sites More sharing options...
elbekko Posted February 22, 2023 Share Posted February 22, 2023 Will be interesting to follow A TDi dragging a Pulse up Norwegian mountains sounds... moderately painful. So I hope the 2.8 improves on that enough. Quote Link to comment Share on other sites More sharing options...
Tobias Posted February 22, 2023 Author Share Posted February 22, 2023 13 hours ago, Gazzar said: No! The whole thing. I've never tackled an auto, so curious and fascinated. Me too, I've been preparing for this for 5-6 years... Quote Link to comment Share on other sites More sharing options...
Tobias Posted February 22, 2023 Author Share Posted February 22, 2023 1 hour ago, elbekko said: A TDi dragging a Pulse up Norwegian mountains sounds... moderately painful. So I hope the 2.8 improves on that enough. Our previous incarnation, a standard 130 CCPU with a demountable camper back, weighing in just short of 4000kg and being 3.2m high was painful. We managed, dropping to 60 or even 40km/h on some slopes, mainly under-fjord tunnels coming back up, but one eye on the cylinder head temperature gauge and one on the road made it. Quote Link to comment Share on other sites More sharing options...
Escape Posted February 22, 2023 Share Posted February 22, 2023 Very interested thread! I've done a rebuild on a standard ZF4HP22 and that was pretty straightforward. Once you start mixing and matching parts, no doubt there will be some challenges. Quote Link to comment Share on other sites More sharing options...
Snagger Posted February 22, 2023 Share Posted February 22, 2023 I think the biggest alteration is tha spray clutch that fails inverted on the 22, so gets replaced with the stronger 24 version. Ashcroft have been doing that fix for a long time and it is fairly well known, so getting details shouldn’t be too hard, especially if you are a customer of Ashcroft so that getting their information isn’t too cheeky. It’d be worth looking into the mods that can give you TC lock-up on command or in other gears, too - I think that is possible on the hydro mechanically governed units as well as on the later hydraulic solenoid controlled (ECU) 24s. Quote Link to comment Share on other sites More sharing options...
Escape Posted February 22, 2023 Share Posted February 22, 2023 The later electronically controlled boxes have a dedicated line for the lock-up, so easy to add a manual switch. In the older ones it would be difficult I think. Quote Link to comment Share on other sites More sharing options...
Snagger Posted February 22, 2023 Share Posted February 22, 2023 There was a method of drilling a hole somewhere in the hydraulic gallery to allow 3rd lockup, at the very least, and perhaps can be done for other gears too, but I don’t have any details. Quote Link to comment Share on other sites More sharing options...
Wytze Posted February 22, 2023 Share Posted February 22, 2023 34 minutes ago, Snagger said: There was a method of drilling a hole somewhere in the hydraulic gallery to allow 3rd lockup, at the very least, and perhaps can be done for other gears too, but I don’t have any details. I did find a talk about that to. But that resulted in sending the body off to get that done. And found something about a solenoid somewhere.. but again.. not enough info on that to Quote Link to comment Share on other sites More sharing options...
Tobias Posted February 22, 2023 Author Share Posted February 22, 2023 2 hours ago, Snagger said: I think the biggest alteration is tha spray clutch that fails inverted on the 22, so gets replaced with the stronger 24 version. Ashcroft have been doing that fix for a long time and it is fairly well known, so getting details shouldn’t be too hard, especially if you are a customer of Ashcroft so that getting their information isn’t too cheeky. It’d be worth looking into the mods that can give you TC lock-up on command or in other gears, too - I think that is possible on the hydro mechanically governed units as well as on the later hydraulic solenoid controlled (ECU) 24s. It's not together yet, but current intention is to use output shaft and "half" of F-clutch from the 300 box and all in front of that from the 4.6-box. Let's see if I can get all parts in sucessfully tonight. My three attempts a few nights ago didn't get quite all the way... The intefaxes between all clutches or modules or how you want to call it are all the same, as far as I have seen so far, so seems really straight forward, as long as you have two complete boxes to mix and match from. As it happens, I have two 4.6-boxes and a few 300tdi's too. At least one benefit of planning for a project for a long time before finally doing it! (planning in my case mostly means collecting stuff "I might need") 3 Quote Link to comment Share on other sites More sharing options...
Wytze Posted February 22, 2023 Share Posted February 22, 2023 10 minutes ago, Tobias said: It's not together yet, but current intention is to use output shaft and "half" of F-clutch from the 300 box and all in front of that from the 4.6-box. Let's see if I can get all parts in sucessfully tonight. My three attempts a few nights ago didn't get quite all the way... The intefaxes between all clutches or modules or how you want to call it are all the same, as far as I have seen so far, so seems really straight forward, as long as you have two complete boxes to mix and match from. As it happens, I have two 4.6-boxes and a few 300tdi's too. At least one benefit of planning for a project for a long time before finally doing it! (planning in my case mostly means collecting stuff "I might need") Did you get a rebuild kit aswell? Quote Link to comment Share on other sites More sharing options...
elbekko Posted February 22, 2023 Share Posted February 22, 2023 37 minutes ago, Tobias said: (planning in my case mostly means collecting stuff "I might need") That's what I'll start calling it I've just been reading a bit on RAVE about how the later electronically controlled boxes work. They really are dirt simple, and it seems almost easier to just operate that one manually. There's 2 solenoids that control the gear selection, one solenoid that control the lockup, and one solenoid to control the line pressure. The difficult one is the line pressure, but that defaults to full pressure, so worst case you have some harsh shifts. There are some aftermarket controllers that would work as well (Haltech for one, which I'm still planning to use at some point - although I haven't collected it yet ). 1 Quote Link to comment Share on other sites More sharing options...
AlWorms Posted February 22, 2023 Share Posted February 22, 2023 7 hours ago, Snagger said: There was a method of drilling a hole somewhere in the hydraulic gallery to allow 3rd lockup, at the very least, and perhaps can be done for other gears too, but I don’t have any details. I've been trying to find those details for a long time! Lock-up 3rd would be brilliant for towing and for country roads around here. Quote Link to comment Share on other sites More sharing options...
Tobias Posted February 24, 2023 Author Share Posted February 24, 2023 Some progress. First RTFM is still valid! I didn't remove the rearmost lump that is screwed from the back wall at first, but it clearly says in the ZF overhaul manual to remove it. Now I could get the F-clutch assembled and but a pieve of PP tubing to keep it together when assembling. I also show some comparison of the F-clutch piece below. 300tdi hydraulic 4HP22 on the right and electric 4HP24 on the left. Wear on the tabs of the clutches can be seen in the 300tdi box, so they were replaced by the clutches from the 4HP24. This 4HP24 has allegedly done less than 5000km, which may be reasonable given the state of things inside. So i use the pieces from it instead pf new from the overhaul kit. Clearly some wear on the tabs on the "cage(?)" from the 300tdi boxe. i use the 4HP24 part. This wear corresponds to the tab wear. After several attempts I got it together. many places to go wrong, but it is very obvious, since the groove for the snap ring holding the C-clutch in doesn't become visible if everything is not sitting right. The PP pipe for the F-clutch was one "secret" that is necessary. Hammering in the planetary gear set into the F-clutch to make the seals go inside properly another. The I used the b-clutch and its snap ring to keep the C-C1-D-clutch pack together. Without these measures I always failed to get everything back together. Obviously with the proper factory ZF-tools it would be easy, and with these three "secrets" i believe I could do it again. The C-clutch snap ring had to be "hammered" int oit's groove in the end, but it was mild violence and what I think is correct. Next step is to get A and B clutches in as well as the rear, but it will be a few days. Tomorrow is play day at the local off roading site. T 1 1 Quote Link to comment Share on other sites More sharing options...
Wytze Posted February 24, 2023 Share Posted February 24, 2023 1 hour ago, Tobias said: Some progress. First RTFM is still valid! I didn't remove the rearmost lump that is screwed from the back wall at first, but it clearly says in the ZF overhaul manual to remove it. Now I could get the F-clutch assembled and but a pieve of PP tubing to keep it together when assembling. I also show some comparison of the F-clutch piece below. 300tdi hydraulic 4HP22 on the right and electric 4HP24 on the left. Wear on the tabs of the clutches can be seen in the 300tdi box, so they were replaced by the clutches from the 4HP24. This 4HP24 has allegedly done less than 5000km, which may be reasonable given the state of things inside. So i use the pieces from it instead pf new from the overhaul kit. Clearly some wear on the tabs on the "cage(?)" from the 300tdi boxe. i use the 4HP24 part. This wear corresponds to the tab wear. After several attempts I got it together. many places to go wrong, but it is very obvious, since the groove for the snap ring holding the C-clutch in doesn't become visible if everything is not sitting right. The PP pipe for the F-clutch was one "secret" that is necessary. Hammering in the planetary gear set into the F-clutch to make the seals go inside properly another. The I used the b-clutch and its snap ring to keep the C-C1-D-clutch pack together. Without these measures I always failed to get everything back together. Obviously with the proper factory ZF-tools it would be easy, and with these three "secrets" i believe I could do it again. The C-clutch snap ring had to be "hammered" int oit's groove in the end, but it was mild violence and what I think is correct. Next step is to get A and B clutches in as well as the rear, but it will be a few days. Tomorrow is play day at the local off roading site. T Really happy with you doing this before i can start 😁 Quote Link to comment Share on other sites More sharing options...
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