Shift console broke

[The Dark Side of Will]

Repaired E30 shift support rod above with E34 rod below:



Z3 1.9 shifter installed. I'm waiting until the new Z3 1.9 shifter for my dad's E24 and the new transmission rod joint(s) arrives in order to measure them for making my own semi-weighted DSSR.

[2002tiiguy]

(1) 26111225624 Flex disc for driveshaft
(1) 26201227191 Centering flange (X5)
(1) 26201225981 Ring cover
(3) 26111204215 Hex bolt M10X42
(3) 26111225054 Hex bolt M10X50
(3) 07129964672 Self locking hex nut M10

[2002tiiguy]

i think thats all the parts for the swap

[The Dark Side of Will]

I removed the T-case today in preparation for replacing the "Rod Joint" at the transmission end of the shifter rod. My new rod joint is here, but the "plastic washer" (really a foam cushion) that goes inside it and takes whatever slack there may be out of the interface between the transmission shift shaft and the rod joint is on the way from a different supplier. There is an aftermarket supply base for the rod joints, but the plastic washer is BMW only.

There's a "large" (96mm bolt circle?) guibo between the manual transmission and the T-case. This size guibo is usually reserved for the "big block" sixes. I guess that's BMW's concession to the fact that when a jackass like me side-steps the clutch at 6200 RPM, the trans to T-case guibo in an iX will see higher loading than the driveshaft guibo of a RWD car. The iX driveshafts use 76mm guibos just like the RWD cars use.

The iX's 96mm guibo is a "common" unit that is still in use today. The catalog description is 96mm/12 meaning a 96mm bolt circle with 12mm bolts. There is a different 96/12 guibo that's called out for the E36 M3, E46 M3, E34 M5 and Z3/Z4 M Roadsters. I wonder if it's thicker than the standard guibo or just made tougher... or internally configured for less driveline lash.

I measure the steel sleeves in the Dorman 935-403 listed for the iX as 1.180 thick... I guess I'll go have CarQuest get in the Dorman 935-182 listed for the E34 M5 so I can measure it.
ETA: Dorman lists the M5 guibo as having a "sleeve length" of 35mm while the non-M5 guibo has a sleeve length of 30mm, which matches what I measured on the ones I have.

The mysteries of the 96/12 guibos solved, I remembered that the E34 540i is rated for more torque than the E34 M5. There is a 105/14 guibo listed for that car. That guibo is also listed for the E38 750i and E46 diesel cars, so it was used on the highest torque cars BMW built at the time, with the exception of... The E39 M5, for which a different part number also called out as 105/14 is listed.

That would be it, but I noticed one application was still missing from my guibo list: E31 850Ci & CSi... They both use 110mm/14's, but with different part numbers. BMW must have been extra confident in the amount of torque their V12 makes, as it actually isn't rated for as much torque as the S62.

For S+G's I looked up the F10 M5. It still uses a 110mm guibo, but the bolt size isn't called out. It's making 600 ftlbs on a cool day, so I guess BMW has altered their drivetrain analysis methods from when they used the same diameter guibo on an 850CSi making 360 ftlbs

//

This is what's necessary to get to the top two bolts on the T-case:






I measure the width of the rod joint where the shift rod goes through as 1.190". I guess I won't be able to use 1.250" aluminum square stock for a DSSR, then.

Rod Joint:

[nando]

unfortunately, that's the wrong joint. there are two types. you need the centered joint. ask me how I know.. :(

maybe you can make it work, but I remember specifically I couldn't use the DSSR with it.

[The Dark Side of Will]

unfortunately, that's the wrong joint. there are two types. you need the centered joint. ask me how I know.. :(

maybe you can make it work, but I remember specifically I couldn't use the DSSR with it.

Umm... how do you know? :-P

The joint I pictured above matches the one that's in my car now.

Do you have the part number for the "centered" one? If it's narrower and will allow me to use the 1.250" aluminum square bar to make a DSSR, it might be handy.

I thought I'd seen a different style with a narrower sleeve end at some point along the way.

[AndrewBird]

Late model RWD cars use the "centered" one, though I think it's actually just narrower, but only on the one side making it symmetrical.

I designed a DSSR like this:



1" square tube with a 1/16" wall works out perfect inside dimensions just needs some mill or grinder work to make it the correct shape.

[The Dark Side of Will]

With steel tube that's probably fine. I was thinking aluminum, for which .060" wall would be pretty thin.

I have a chunk of 1.250" aluminum square bar, but I can grab some 1" steel square tube if the dimensions indicate that might be a better choice.

Is the DSSR you pictured for your 525iX?

Has anyone done a DSSR for a 325iX? Are there any gotchas in terms of T-case, shifter support rod or guibo clearance?

[AndrewBird]

I wouldn't even think twice about aluminum, it's a lot stronger than most think. The only thing I would be slightly concerned about is the holes elongating over time. Drilling the holes oversize and using a bushing would fix that.

I think the one picture is RWD E30 length, but I can't remember now.

[The Dark Side of Will]

Aluminum's issue is fatigue rather than strength.

What's the torque spec for the trans-to-T-case guibo bolts? We just did the guibo on my dad's E24 based on the E28 Bentley which specified 90 ftlbs for the same 96/12 guibo.

Even though that's not an extreme spec for a 12mm bolt, the guibo comes with new bolts. However, the trans side bolts are pressed into the output flange like lug studs, so not really any choice on re-using them.

[nando]

I don't recall if it was narrower. But I know it didn't fit with the DSSR, it wasn't even close.

[The Dark Side of Will]

I elected to forego the DSSR this time around.

You can see the end of the shift shaft above the trans output flange in this photo:



This shows the new (wire lock) vs. old (band lock) rod joint, as well as the other shift linkage parts. The orange thing is a foam cushion that goes into the rod joint before it is installed on the shift shaft.



Like this:



Rod joint installed:



Shift linkage assembled:
You can see the clips on the side of the shift support rod which hold the back up light wiring into the channel on the side of the rod.



The intricate features of the installation interface of the manual transmission transfer case.



Rotated the input shaft to see more of the craziness:



These are the o-rings for the driveshaft and sprocket snout, as well as the part number for the plastic "covering cap" that connects and seals the two o-rings. These o-rings don't just keep junk out of the driveshaft splines, they keep the grease *IN*. My o-rings were so brittle they cracked when I tried to remove them. There was a ring of schmutz around the front output from where the grease had leaked out and schmoozed all over the front of the T-case.

[driftxsequence]

Thanks for the great photos. I am trying to drop my transfer case and those top bolts are a pain. Did you have the trans lowered or raised when breaking the bolts loose?

Should I have a jack to catch the t-case or is it man-handable?

[The Dark Side of Will]

Trans was lowered. The shifter has to be dropped in order to reach through the shifter hole with a tool and this can only be done with the T-case and trans lowered.

The T-case is ~60# I think... I'm pretty strong and removed/installed by hand under the car. If you're not a beefcake, you probably want something to hold it up. It will mostly stay in place via the alignment dowels and guibo centering pin, so you shouldn't have to be supporting it's weight while you get a bolt in. I was able to start both of the top bolts from underneath and run them all the way down with my fingers, then come from above to tighten them.

[driftxsequence]

That's exactly what we ended up doing. I did have a helper raising and lowering the transfer case.

shifter slop is nearly all gone. Well worth the effort.