E30 M3 S62 Build - Loads of queries about 4x4 drivtrains

[nando]

Driveline components are rated for a lot of things, including vehicle weight.

*THIS* is exactly what I'm concerned about regarding BMW T-cases:

this is a lubrication and maintenance issue. also, you can extend the splines at least another inch to give more contact area. BMW still uses this same basic design. The U-jointed transfercases still have that splined section, only there's a flange for the shaft to bolt to, instead of a one-peice shaft/spline.

The pinions in the center diff don't inspire confidence either...

why? have you EVER seen one damaged? they're basically the same size as the ones used in the diff, and transmission, and anywhere else in a BMW drivetrain.

[The Dark Side of Will]

Driveline components are rated for a lot of things, including vehicle weight.

*THIS* is exactly what I'm concerned about regarding BMW T-cases:



The pinions in the center diff don't inspire confidence either...

[nando]

The torque/horsepower debate is only relevant if you're comparing engines with very different RPM ranges. A 400 HP turbo M20 and a 400 HP S62 are going to have similar torque because they make peak power at similar RPM.

This is *NOT* the 180 HP Caterpillar vs. 180 HP Yamaha comparison.

What pictures did you find of the E34 T-case? What is its designation?

The E30 T-case is the ZF A-95

http://www.garlington.biz/Ray/BMW/325ixDriveTrain.htm

http://www.garlington.biz/Ray/BMW/325ixDriveTrain.pdf

drivetrain components are still rated by torque, not horsepower.

http://boards.bmworg.ru/viewtopic.php?t=2835

[nando]

there was a guy on here with a turbo ix (in norway, derp) that went through 6 or 7 transfercases.

but he had something like 700-800hp.

he broke front diffs, not transfercases..

[The Dark Side of Will]

There are limited pictures online of the E34 transfercase. I was hoping to use parts of it, but it became apparent that although similar, it's really different inside. the gears are much bigger as is the chain.

torque.. forget about HP, that's a function of how fast you're turning at a given torque level. torque breaks stuff. :p

The torque/horsepower debate is only relevant if you're comparing engines with very different RPM ranges. A 400 HP turbo M20 and a 400 HP S62 are going to have similar torque because they make peak power at similar RPM.

This is *NOT* the 180 HP Caterpillar vs. 180 HP Yamaha comparison.

What pictures did you find of the E34 T-case? What is its designation?

The E30 T-case is the ZF A-95

http://www.garlington.biz/Ray/BMW/325ixDriveTrain.htm

http://www.garlington.biz/Ray/BMW/325ixDriveTrain.pdf

[Kershaw]

there was a guy on here with a turbo ix (in norway, derp) that went through 6 or 7 transfercases.

but he had something like 700-800hp.

[nando]

There are limited pictures online of the E34 transfercase. I was hoping to use parts of it, but it became apparent that although similar, it's really different inside. the gears are much bigger as is the chain.

torque.. forget about HP, that's a function of how fast you're turning at a given torque level. torque breaks stuff. :p

I've *never* heard of a turbo guy breaking a transfercase. I've heard of countless front E30 diffs breaking though. If you've heard of one, you'd be the first. ;)

[The Dark Side of Will]

the 525ix transfercase is a little beefier internally than the 325ix (bigger chain, bearings, gears),

Source for this info?

and the 325ix transfercase really doesn't have trouble with 300-400 ft/lbs of torque so a 525ix transfercase should be just fine.

Just how big is the pool of 400 HP E30 iX's? I bet I can count them all on the fingers of one hand. Don't forget that in stock configuration, the front diff is the "fuse". When used with the stronger 168mm front diff, the next weakest link will rapidly become apparent.

[nando]

If you used a ZF 5-speed, you could also use a 525ix transfercase. It's got an electromagnetic clutch - with some clever electronics, it wouldn't be that hard to control (you'd need wheel speed inputs and a PWM output). You can definitely get them in the UK, for not all that much.

You can get the rear housing of the 525ix transmission for about $200 and convert any ZF 310/320 to mount a 525ix transfercase to it. It would require a U-jointed shaft of course. the 525ix transfercase is a little beefier internally than the 325ix (bigger chain, bearings, gears), and the 325ix transfercase really doesn't have trouble with 300-400 ft/lbs of torque so a 525ix transfercase should be just fine.

[The Dark Side of Will]

Yes I looked at this, but how do you mount the box to the engine? which clutch would you use and with which flywheel? how would the starter work?

If only I could find something v8 with a t case already mounted.

Seriously, read my thread on E30Tech.

http://www.e30tech.com/forum/showpost.php?p=1240811&postcount=44

http://www.e30tech.com/forum/showpost.php?p=1261232&postcount=258

And a post in another thread that's linked from mine...

http://www.e30tech.com/forum/showpost.php?p=1261654&postcount=164

[craiggroves91]

Pics or its not happening

[Turk]

You can just drive down the street and buy things like this, for example: ;)
http://www.ebay.com/itm/150754800982

Yes I looked at this, but how do you mount the box to the engine? which clutch would you use and with which flywheel? how would the starter work?

If only I could find something v8 with a t case already mounted.

[The Dark Side of Will]

Since you have different parts available over there, you might go a different way for the driveline.
For example, you should be able to find the taller front end gearsets and diffs that I couldn't get here that would make BMW's transmissions more attractive.

The ZF 5 speed, for example, might be tolerable with 2.93 diff gears, but certainly wouldn't be with 3.64 gears, whcih are the tallest I can get here in the US. The USDM TR6060 works much better with 3.64's.

You can just drive down the street and buy things like this, for example: ;)

http://www.ebay.com/itm/150754800982

[Turk]

do u know of any t-cases available in europe which could suit the same purpose? Findling a silverado tcase here is going to be like finding rocking horse shet :D

how are you going to make up a plane extender for the gearbox u have chosen? dog have to use a different clutch kit?

[The Dark Side of Will]

So am I right in think diff wise you have managed to get the x5 one in BUT it fouls the various racks you have tried on the banjos?

When will you be performing the T-case Yoke-an-ectomy?

Which other t-cases have you looked into?

I know what I have to do in order to get the rack and diff to play nice... but I have another project that's closer to being on the road and consuming my time right now.

I won't be doing what I described to a BMW T-case... I'm going to a domestic T-case along with my domestic 6 speed transmission. The one that's caught my eye for now is the NVG 149 used in the Silverado SS pickups. It's single speed full time with ~35/65 torque split and a viscous coupling. It's functionally identical to the BMW unit, but built for a 5000# truck with an engine that makes 400 ftlbs of torque.

I was talking about using the X5's DSC for the transfercase, not for the M5's oil pan/pump. I don't think any of that would work with the X5's oil pan anyway.

regarding the transfercase and shaft alignmnent - I don't think it would be that much of a stretch if you didn't mind cutting into the trans tunnel. the output shaft is pretty low, almost the bottom of the engine - so even though it's 4" closer to the drivers side, it's not ilke you have a shaft running right next to your knees or something.

I don't like the idea at all of using U-joints, there's probably a reason BMW makes all their shaft alignments as straight as possible. but, sometimes you gotta do what ya gotta do. :)

Obviously, putting the M5's active sump baffling and valves into an X5 oil pan will require significant fab work.

I think that cutting into the trans tunnel for the sake of the driveshaft is going to make things very annoying for your right foot and probably the gas pedal as well.

BMW built the shafts the way they did because straight shafts are cheaper than u-jointed shafts.

When the packaging requirements of the E46 and E90 dictate going to a U-jointed shaft, they did so. Those shafts don't give nearly the same kind of problems as the straight shafts... Across the industry, unjointed shafts are very much in the minority. Not a thing in the world wrong with a u-jointed drive shaft.

One of the important packaging concerns in an E30 iX, for example, is that the seat fore/aft travel isn't affected by the AWD. This has implications as deep as the internal layout of the T-case. BMW went with a gear rather than chain drive T-case in the E46 to improve packaging relative to T-case intrusion into the driver's side transmission tunnel.