2 years later...another guibo ready for replacement

[M3M3]

could the evidence of rubbing on the tranny be left over from the last guibo you had issues with? i don't see evidence on the current guibo from the pics. the bottom of the shifter shaft does not look polished either.

[jgerock]

could the evidence of rubbing on the tranny be left over from the last guibo you had issues with? i don't see evidence on the current guibo from the pics. the bottom of the shifter shaft does not look polished either.

Good comments..

Here are the pics after I pulled the El Cheapo MTC brand guibo off after the maiden voyage (all of about 5 miles) and cleaned off most of the rubber bits.

Package from inferior guibo

[jimk]

I got to thinking the guibo should not run on a plane forward enough to touch the case boss where the shifter comes through. I dug thru my old photos and came up with this one. (It is a crop from a larger photo and I had to lighten it a bunch to see the area of inteerest). The boss can barely be seen, but it appears the plane of the output flange to be clear of the boss. The guibo forward edge is on the same plane when installed. So it seems something is pushing the driveshaft and trans together(?) for the guibo to rub where the rub marks are on your photo. Or your flange is more forward than it should be? Maybe you want to check the layout on yours.

[jgerock]

Thanks for the picture Jim. I'll check that tomorrow although I think my output flange coupling sits higher than the adjacent boss.

Today's work involved several hours under the car along with fetching tools and borrowing mlytle's vice so I could modify a stock 4-speed bracket (Thanks Marshall!).

After trying to center the trans between the framerails, I was able to get the lower holes drilled and (4) bolts temporarily installed for the brackets. Tough to do by yourself.

Here is my old stock 4-speed bracket (too long) being tried

The stock 4-speed body tabs measure about 3" (roughly 76mm) up from the frame rails and I've pushed the trans up almost as far as I can to mark the new bracket locations. They end up being the same 3" as the stock tabs.

Here is the shortened (1/4" each end) 4-speed bracket installed with new tunnel brackets (top bolts yet to be installed)

You have to pull up some of the interior carpet and insulation to gain access to the nuts/washers, so I accidently popped the accelerator pedal off the floor nubs. Interesting modification by a PO.

I still have to drill and mount the top bolts. Note the driver's side tab interferes with the shift tower support (triangular brace). I'll modify the brace or just try to find a pan-head bolt so it doesn't touch.

[M3M3]

nice work Jim!

i have a NEW stock gas pedal for you. toss that thing you have.

and get that nasty looking shortened bracket off that car. do not put it back on until it has been properly prepped and painted! :-)

looks like length and mount hole came out right.

[BillWilliams]

That was a lot of work today. I have never liked that brace that holds the shift platform up. It seems to get in the way of whatever you try to do down there. You can send a bolt down through the top of the tranny tunnel into the rear of the shift platform and get rid of that brace.

[jgerock]

The mods made at your place worked out just right. No more cutting or filing needed. Definitely will clean and paint that old bracket before final installation.

Felt funny sitting on the floor with one arm inside the car with ratchet and 10mm socket, the other under the car with the allen wrench and my chin pushing down on the carpet against the door jamb. That would have been a good pic if someone was here.

[jgerock]

That was a lot of work today. I have never liked that brace that holds the shift platform up. It seems to get in the way of whatever you try to do down there. You can send a bolt down through the top of the tranny tunnel into the rear of the shift platform and get rid of that brace.

I like the way this one sits above the tranny bracket instead of from below. Should be simple to make it work.

[LarsAlpina]

E21-like mount can be used to hold 02 shift platform up, too. I would not just screw it to the tunnel without a rubber absorption. 8, 9 and 10 here:

http://www.realoem.com/bmw/showparts.do?model=1733&mospid=47175&btnr=25_0176&hg=25&fg=05〈=enUS

Sent you another email Jim.

Best regards, Lars.

[bnam]

Following this thread closely as I too have the U bracket from Rob. I built a DIY measuring tool to see how my set up compares to the 80mm as shown in the factory instructions.

This was the tool I built to clear the exhaust. The standoff on the frames are 45mm and then I locked the 2 nuts on the central threaded bolt to be at 125mm above the aluminum L-bar.

This pic taken before I locked down the central reference ht.

This blurry pic shows that the top of the flat bar is about one nut lower than 80 (about 75 or 76mm vs 80).

I put in 2 flat washers which total about 5mm. I had to put it on top of the rubber mount between the mount and the gearbox.

I've got it back on now. I am concerned that pushing it up has narrowed the gap a bit between the shift linkage shaft and the guibo.

Byas

[Lee]

One motor mount that I have always loved was the squarish Bavaria unit. It is quite stiff and designed for a heavier motor and heavier tranny.

Lee

[ifayeoh]

Interesting issue, i have had to change my guibo as well after about 15k, i was using the aardvark tab method. Alignment was good and so was deflection of loosely mounted quibo, nice rotation and not excessive spread and quibo still cracked.

I decided to try the cantilever method using one of Jakes U-bracket so time will tell how that turns out.

When i had the tabs bolted in i dont remember having them in same plane as the original tabs that are used with the 4-speed. the 5speed is longer and if i recall correctly they were lower than the factory. Did you check drive shaft alignment and guibo deflection prior to drilling holes for tabs? i think that is key when installing your new tabs from Lee.

yeah get rid of the shift bracket brace or maybe just use a cap head for more clearance.

hth,

Frank

[c.d.iesel]

how about this :

is there a spacer that might be missing on the output

shaft IN FRONT OF THE 3-HOLE FLANGE!? -which

would move the flange away from the box a few 0.00 mm's

which would resolve the guibo contacting the

case just below the shift shaft ??

there is a spacer in two thickness

25 x 36 x .1 mm

25 x 36 x .3 mm

if you look at parts frame:

1979 E21 USA 23_0700 Getrag 245/2/4 Gear Wheel parts

there are a few threads to spare for the nut

to still hold the flange adaquately?

[M3M3]

I've got it back on now. I am concerned that pushing it up has narrowed the gap a bit between the shift linkage shaft and the guibo.

Byas

folks...you can push up the tranny as far as you want and YOU WILL NEVER CHANGE THE GAP BETWEEN THE SHIFT LINKAGE SHAFT AND THE GUIBO! i see this comment alot. think about it. the shift linkage shaft is part of the tranny. so is the guibo. they aint gonna get closer together unless you crush the entire transmission or bend the linkage shaft.

[jgerock]

Byas (bnam): Your car is using the smaller diameter 8-bolt guibo so you shouldn't have any problems.

CD (and others via e-mail): The output shaft coupling DID have at least (2) shims between it and the bearing. I was careful not to remove them when I replaced the output shaft seal and housing gasket.

Funny thing about my problem.. I was just reviewing some old pics I took of the parts that came with the eBay transmission (before I chucked some of them). Take a look at the old Jurid brand guibo that was with the tranny (not attached):

Here is a picture showing how bent the shift rod was (most likely shipping damage)

Picture from the eBay ad

Did this problem exist when it was originally installed in the '81 320i? As Lars pointed out in his e-mail to me, he wonders if the car was in an accident and did some damage that could be the issue? Not sure, but the tranny is very quiet, shifts smoothly and I have zero driveline vibrations.

???