ZF 4HP22 bolt pattern

dokatd · Post by **dokatd** » Sat Jan 31, 2009 11:38 am

Ok, so its my understanding that the 4HP22 is being used on the TDs. And that the TD manual tranny is swappable to the 712/710 engine. So, does that mean that the bolt pattern of the Puch Gas engine is compatible with the standard 4HP22 bell housing or is there a special tranny housing. I dont care about the other aspects of a swap, just the compatability of the transmission bell housing to the standard 712/710 engine.

David Dunn · Post by **David Dunn** » Sat Jan 31, 2009 12:00 pm

It is not a straight swap... the bell housing are different, plus a few other little alterations needed to the manual trans.

dokatd · Post by **dokatd** » Sat Jan 31, 2009 12:08 pm

Im not sure I understand your post. Are you saying the Manual transmission bell housings are different from the TD to the 712/710.

What are the chances that the 712/710 gas engine has a standard pattern for the transmission. And does anyone have measurements for the pattern.

David Dunn · Post by **David Dunn** » Sat Jan 31, 2009 12:42 pm

Erik712m · Post by **Erik712m** » Sat Jan 31, 2009 5:36 pm

Dokatd, Can I ask what you are trying to do?
http://luuk.xs4all.nl/bmwboeken/bmw%203 ... F4HP22.pdf

Dave, Did you ever look at the six speed Ideas for your TD?

Profpinz · Post by **Profpinz** » Sat Jan 31, 2009 6:11 pm

The manual ZF box used in the 716/718 range is basically the same as that used in the 710/712 ...different ratios etc but, it is from the same ZF S5 family.
The automatic is a ZF 4HP22 .... from the same family as that used in Range Rovers from the mid 80's.

The bell housing used to mount the ZF manual gearbox to a air-cooled Pinny is different to that used in a TD (different part numbers).... different flange pattern on the engines.

The convertor housing used to mount the auto box to TD is unique to the TD motor (as everybody knows there was no factory auto option on air-cooled Pinnys).

........So basically no matter how hard you look you won't find a factory air-cooled motor to auto transmission "adapter" (and in any way, it's unlikely the 4HP would work with that motor's torque characteristics/ specifications)

If you were "desperate enough" to really want to do it, you'd have to either fabricate a convertor housing/bell housing or "cut and shut" a 710/712 bell houing to a TD convertor housing.

BTW...Has anybody ever seen or heard of an auto air-cooled Pinny....I haven't, but that doesn't mean that someone around the world hasn't tried / succeeded!

dokatd · Post by **dokatd** » Sat Jan 31, 2009 8:06 pm

Well I was one of the first in the US to swap a manual D-90 to auto, so why not a pinz. The auto will make up for alot of the pinz short comings. Contrary to what you would think in regards to gear ratio, the auto will provide better rock crawling control, and give you an overdrive for highway use. It will require a few engine mods as well, but its nothing a turbo and propane cant fix. Now its time to design the bellhousing adapter. Waiting for ZF to send me some bell housing dimensions. There are about 6 different factory bells for the ZF 4HP22. But it still might be better to modify the manual bell for the auto. Anybody got a spare manual bell housing they can part with.

Erik712m · Post by **Erik712m** » Sat Jan 31, 2009 9:29 pm

If you are going to make a bell housing adaptor. Why not just Use the ZF 6HP26? First gear will get you closer to the factory 5.33.

http://en.wikipedia.org/wiki/ZF_6HP26_transmission

dokatd · Post by **dokatd** » Sat Jan 31, 2009 9:55 pm

Length and the fact that autos dont work the way manuals do. Due to the effect of the torque converter, the first gear ratio of an auto is not the "true ratio that the engine feels" . I just got done crunching the numbers, and with the proper valve body and torque converter, you can achieve almost identical crawl ratios and significant overdrive ratios. First gear in the auto config with a 712 t-case will be better than 1st gear in a 710. The key is to get a torque converter that locks up at the right RPM. Looks like I will start with a complete setup from a volvo 740. I have to go and do some visual inspections of the pans etc. Assuming you have the power and the balls, a 712 would be able to exceed 85MPH. This means the overdrive will be almost useless untill you up the engine output a bit.

Also consider that the 4HP22 is like a weed in junkyards. I can pick about 15-20 of them from one yard here for $99.99. And contrary to what people like to assume, they are very stout and would be virtually indestructable in an air cooled pinz.

Profpinz · Post by **Profpinz** » Sun Feb 01, 2009 1:56 am

Well I was one of the first in the US to swap a manual D-90 to auto, so why not a pinz

I think you'll find a Pinzgauer a totally different animal to any LR!
(I know LR's quite well, being on committee of Australia's largest LR Club....1000 members...and some of them as, if not more, fanatical about LR's as I am about Pinzgauers!

).

LR componentry is quite modular and transmission/motor/drivetrain swaps are fairly easy given the commonality across the Defender, Discovery and Range Rover range, but no such luxury on a Pinny.
The air-cooled motor in the Pinzgauer was designed specifically by SDP and is unique to the vehicle....it's not used in anything else worldwide!
Even the TD is an "easier" recipient to customise as many more of the components are common (motor = VW, auto = RR etc, etc)

That's one of the things I really appreciate about people doing various modifications or building Pinzgauer specific componentry.
Today, many people believe "modifications" are simply a matter of buying a non-genuine or OEM part that is reputed to be bigger and better and just bolt it in place.... not so with the Pinny, as most of the time you have to design, fabricate, build, assemble, test, tune and modify the mods all yourself... just ask Jim or Jake or many of the other members who have done it!

I have no doubt that if one REALLY wanted an auto in a 710/712 that's it's possible to achieve, it's just that you won't get the luxury of any commonality across other brands in regards to componentry, or input from people who have gone before... and don't think it's going to be a simple parts swap like a lot of vehicles!
I'm sure there will be a lot of custom fabrication and construction, lots of hair pulling and debate, but if you like a challenge go for it!...and good luck!

BTW....Don't forget to post pics if you go ahead!

Erik712m · Post by **Erik712m** » Sun Feb 01, 2009 4:44 pm

Well, I now 70 mph in a pinz is scary, not so much with the vibration but just the slittiest movement of the wheel puts you in the next lane. But isn't the pinz engine designed to run and preforms the best at 2500 rpm? Wouldn't this put your speed at 40 to 45 mph?

dokatd · Post by **dokatd** » Sun Feb 01, 2009 7:01 pm

For the most part I will spare you blowing my own horn. However I am far from a component swapping tool jockey. If you are a rover fan you might be aware of frankenRover owned by Bill Ritchie here in the states, that truck was built primarily by me. And other items on my build list are Ford 9" Dana 60 35 spline Rover axles. Yes thats an axle composed of major parts from all those axles. I dont care if its a component swap or a complete refabrication of major parts. If it makes since I will make it happen. I will certainly take pictures as i do the swap. It will likely take me some time as I am short on funds. But I do not anticipate it to be a difficult swap with all my current information.

If anyone has any good thoughts, please feel free to let me know.

Erik712m · Post by **Erik712m** » Sun Feb 01, 2009 7:27 pm

If anyone has any good thoughts, please feel free to let me know.

Go for it!!

After all if it works with the ZF 4HP22. It should work with the ZF 6HP26. I think the case is shorter buy an inch and a half on the 6hp26.

And if it doesn't the only thing you have wasted was time.

On a side note how much horse power do you think you will have to add to keep the auto from shifting like a row boat?

dokatd · Post by **dokatd** » Sun Feb 01, 2009 7:45 pm

The 6 speed might not work simply because the bell housing is fixed to the casing. You cannot clock or replace the bell with another bell. This might not be a huge deal since I might end up with a bell adapter.

Honestly it should act fairly descent with stock power. However im going to shoot for about 150HP give or take. I havent researched the engine design enough yet to be able to estimate a true realistic number.

Erik712m · Post by **Erik712m** » Sun Feb 01, 2009 7:56 pm

150Hp you'll have to rebuild the hole thing. Or drive it like a Porsche and not american muscle.

The original engineers only designed the drivetrain the handle 120HP.

I think it would be cheaper to build a bell adapter than use the factory bell. remember if it doesn't work the factory bell is something like $260.00 or higher.