24V AWD Swap Knowledge Base

[The Dark Side of Will]

So a little while ago I was looking into the 6 speeds. First of all I don't think they're worth it. As Nando said they are heavier and I think by quiet a bit. Also the lack of a 6th gear can be fixed by the diff ratio you choose. For example I see S54 6 speed guys go for a 3.73 while the 5 speed guys go for a 2.97. I've thought about the bracket idea a lot and had a lot of good ideas too, but in the end I just didn't feel it was worth it. Its expensive enough to do a 24v swap into an ix and I made the decision that the money it would take to do the 6 speed would be better off being spent else where. If you still want to look into the 6 speed then check out S54 Z3 6 speed conversions for the dimensions and length. The have to get custom drive shafts and everything done when they do the 6 speed conversion. You also might need to cut up the transmission tunnel too, I think the 6 speed is like 3-4 inches longer and I don't think theres enough space to push it back that far.

As for the 525ix transmission and transfer case. Again I wanted to go the route but two things stopped me, first the money again, and secondly diff ratios. With the Zf I was looking at wanting to use a 3.34 or 3.46 diff ratio, the problem is that the X5 only uses a 4.10 and 3.64 in North America. There is a 3.07 for the Diesel over in Europe, but I felt that would be to low. How ever according to Nando and these guys a 3.64 diff ratio with a Getrag 260 would be perfect so I opted to keep with the 260.

So in summery I don't think its worth it. This is coming from someone who was in the same boat as you, but after a lot of consideration I realized the cost and R&D in doing that wasn't going to pay me back, so to speak. The only benefit I really see to the 6 speed or 525ix parts is just to list them on your "mods" sheet. The cost of the 6 speed plus custom driveshaft and brackets will never make back your money in better MPG and it won't give you a performance advantage either. As for the e34 TC yes it would be cool, but its costly and theres nothing really wrong with the TC that came with the 325ix.

A lot of good info here. The rear end ratio is the killer.

BMW doesn't do tall overdrives. The tallest top gear in any BMW stick is already the 0.81 fifth in the Getrag 260 (&265). IOW, a 6 speed won't give you any lower RPM on the highway than the trans that's already in the car.

At the other end, the 6 speeds do have shorter 1st gears, but a high powered engine in an E30 doesn't need a deep first. That's why I suggested swapping the CTS G260 gears with 3.46 first into the proposed frankentrans.

The ZF has a 1:1 fifth, and thus needs much taller diff gearing than the 260. While tall gears are available in the E46 diffs, they have to be swapped over to the E53 diff. The 3.07 E53 diff uses a different case than the numerically larger ratios in order to have clearance for the larger pinion. This means that even to have the parts to build a tall E53 front diff, one needs to get both the 3.07 for the large pinion case *AND* a Euro market E46 diff for the gears.

...*AND* build a matching rear end.

Overall, it's far easier to snag the 24V G260 case and swap it. You don't necessarily have to overhaul the trans, and the front case half can be swapped with hand tools and a steering wheel puller.

[The Dark Side of Will]

So what Ill do then is use the E53 FDA along side with the E34 transmission and transfer case.

I feel like this may be a stupid question but the E53 half shafts do they fit the e30 ix hubs? Also with the diff options would i be able to use the 2.93 gears? Are any of BMWs front gears LSD?

The E30, E34 and E46 all use the same splines and such on the CV joints. It's likely that the E53 is similar, but has not been tested yet.

The tallest E53 front diff is a 3.07 from the X5 3.0d. You can *probably* swap in 2.93 gears from an E46, but the E46 diff does not bolt up to the E53 pan. I've never seen setup information for how to shim the gears in any BMW front diff, or sources for the shims.

Your best bet is to get it running with a diff you can bolt in, *then* try to change ratios.

The limited availability of BMW ratios is why I went toward the TR-6060.

[Bimmer_man]

oh I know it would just make things easier and easier to get parts.

If the front diff wasnt fragile (compared to how you can drive the rwd e30 ) i would just franken pan and use the M20 arms.

My whole point of doing all this is to upgrade the front diff. haha this is a huge pain but will be worth it in the end.

[nando]

well even if we did have it, it's still not a bolt in swap.

aside from nisse, the only successful 24v swaps have been frankenpans using the stock E30 ix drivetrain.

[Bimmer_man]

these things would be so much easier if the stupid usa got the damn e34 ix.

[Nisse Järnet]

I measured my ZF 320 and 420g and the 420g is 10cm longer. There's no way you can fit that gearbox + tc without serious work.
I'm looking into gs6-37 or 53 6 speed and atc-300 tc that should fit hopefully because it doesn't have a guibo between the gearbox and tc.
But the atc-300 is alot more advanced to control electronically...

[Bimmer_man]

Thats a lot of good information.the 6 speed would be a large sum of money to swap into it. Got to love the complexity of the ix vs the rwd e30 haha. I think thats part of the reason i love the ix. Ill have to do a bit more research into what im after then.

[stonea]

So a little while ago I was looking into the 6 speeds. First of all I don't think they're worth it. As Nando said they are heavier and I think by quiet a bit. Also the lack of a 6th gear can be fixed by the diff ratio you choose. For example I see S54 6 speed guys go for a 3.73 while the 5 speed guys go for a 2.97. I've thought about the bracket idea a lot and had a lot of good ideas too, but in the end I just didn't feel it was worth it. Its expensive enough to do a 24v swap into an ix and I made the decision that the money it would take to do the 6 speed would be better off being spent else where. If you still want to look into the 6 speed then check out S54 Z3 6 speed conversions for the dimensions and length. The have to get custom drive shafts and everything done when they do the 6 speed conversion. You also might need to cut up the transmission tunnel too, I think the 6 speed is like 3-4 inches longer and I don't think theres enough space to push it back that far.

As for the 525ix transmission and transfer case. Again I wanted to go the route but two things stopped me, first the money again, and secondly diff ratios. With the Zf I was looking at wanting to use a 3.34 or 3.46 diff ratio, the problem is that the X5 only uses a 4.10 and 3.64 in North America. There is a 3.07 for the Diesel over in Europe, but I felt that would be to low. How ever according to Nando and these guys a 3.64 diff ratio with a Getrag 260 would be perfect so I opted to keep with the 260.

So in summery I don't think its worth it. This is coming from someone who was in the same boat as you, but after a lot of consideration I realized the cost and R&D in doing that wasn't going to pay me back, so to speak. The only benefit I really see to the 6 speed or 525ix parts is just to list them on your "mods" sheet. The cost of the 6 speed plus custom driveshaft and brackets will never make back your money in better MPG and it won't give you a performance advantage either. As for the e34 TC yes it would be cool, but its costly and theres nothing really wrong with the TC that came with the 325ix.

[Bimmer_man]

this six speed is longer by more than an inch I can pretty much guarantee that. I have a few ideas on how to get the transfer case to mount but im going to have to get a look at a 6 speed and take some measurements.
it looks like the bracket thats supposed to be the transmission mounts would be where i mount the transfer case via an adapter. it actually looks like its defiantly possible.

Overall a 24v swap and a 6-speed awd ix is going to be really costly. good thing i only have one project car haha.

[nando]

if you use the E30 transfercase, it might not be so bad. It depends on the length of the 6 speed VS the Getrag 260. I'm willing to be it will be longer, but I don't know how much. There is some adjustment built into the rear shaft, but not more than an inch or so.

[Bimmer_man]

Sweet, well thats good to know. It looks like i just need to grab a zf 6-speed and figure out a way to mate it to a transfer case.

Thats going to be quite the endeavor just to see if it will work. Im sure that ill need to shorten the rear drive shaft and DEFIANTLY a custom front drive shaft.

[nando]

the manual is a ZF. GMs were only slushboxes.

you could do it with a RWD trans but you'd have to build a brace/mount plate to bolt the transfercase to.

[Bimmer_man]

it looks like the e46 uses the 96mm so thats good there. But from what youre describing i would have to have a whole new rear section for the 6 speed to work with the transfer case. Am i understanding that correctly?

it dosnt look to be possible unless i use the e46 xi transfer case. The 330xi used the GM transmission GS6-37BZ/DZ. I believe thats a GM transmission. Getrag and ZF dont use those kinds of ID codes for there transmissions.

Well there goes the 6-speed idea. haha it was worth a look into i suppose.

So what Ill do then is use the E53 FDA along side with the E34 transmission and transfer case.

I feel like this may be a stupid question but the E53 half shafts do they fit the e30 ix hubs? Also with the diff options would i be able to use the 2.93 gears? Are any of BMWs front gears LSD?

[nando]

E46 doesn't haven an output flange. it works like the automatics on the E30, the shaft goes right into the transfercase. you would have to use a RWD transmission.

luckily the transfercase input is a "large" flex disc, 96mm. Later BMWs got even bigger though so hopefully the RWD E46 is still 96mm.

no. there's a Getrag 260 with a bellhousing for a 24v motor. it was part of the transition year of the M50 into the E34, Europe only. you'd have to build a new Getrag for the ix using the front half of that trans, and the rear half of the ix trans. But it would bolt up like stock.

[Bimmer_man]

ill have to look into the output flange if the only one i can use is the e46 transfer case then i really dont want to deal with machining a whole new output flange.

just to make sure i understand this right though. when you mentioned the 24v bell housing where you suggesting the e34 transmission as a whole? I just want to clarify.