5 Speed Install Help - Alignment and Flex disc/guibo trouble

[felix_666]

In the process of installing a 5 speed.

Unsure if the flex disc/guibo should look like it does.

Background info:

The diff is all the way back.

Tranny flange and driveshaft flange are straight from what I can tell. I measured using the straight edge trick - attaching straight edge to bottom of tranny (next to drain plug) and measuring distance between top of straight edge and bottom of driveshaft. Did this closest to the flanges = 108/109mm, and next to centre bearing = 108/109mm.

I also measured the distance between the frame rails and the bottom of the tranny mount (big green e21 mount) = 85mm. I know this is meant to be 80mm but if i do this the previous measurements have a greater difference of around 8-10mm.

Stupidly I didn't measure everything before I got the driveshaft chopped, I just based my numbers on theory.

My concern is that the driveshaft is a couple mm too long, creating tension and therefore the slight deflection in the guibo???

I'm hoping someone will say I'm overthinking it. Thanks for reading and any help.

[c.d.iesel]

= BAD. make adjustment

[ClayW]

Yes, you're driveshaft is too long. Deflection in the guibo is what causes them to prematurely wear out. I would guess that yours would last about 1000km if you drove it like that.

Take the driveshaft out, center the differential and remeasure.

When I did my first 5 speed conversion, I somehow ended up with a driveshaft that was exactly 1 inch too long. No way around it; I had to get it re-shortened.

[c.d.iesel]

[felix_666]

Damn.....

[TobyB]

Yup.

I had that happen once, too.

t

[M3M3]

ALWAYS measure the length of the driveshaft you need for 5spd conversion after tranny installed and order what the measurements say.

[bnam]

Yeah, mine came like that from the PO. About 1/16-1/8" too long even after diff all the way back. I intend to resize it by another 1/4". But, it's been on the car for now going on 4000+ miles (3000+ by me).

Byas

[OriginalOwner]

so, thinking outside the box ......

if the driveshaft is, for example, 5mm too long, why can't you just shave 5mm off the thickness of the guibo ??

that guibo I see above in bnam's picture looks like the one attached to my 4-speed ..... lots of "spare" thickness there ??

Seems to me the real constraint is the steel cylinders in the guibo through which the bolts pass .....

What are the engineering constraints to the guibo design such that less thickness would cause a problem ??

Cheers,

Carl

[tim385]

You may have tried this ...you can move the motor a bit, loosen off your mounts a bit give the engine a bit of a shake , you can usually pick up 5-10mm, but watch the fan -radiator clearance.Just a thought.

[NickVyse]

I split the e21 driveshaft in my NK and shaved about 3mm off the middle joint to get the length I needed - worked perfectly and didn't effect the balance (make sure it goes back together in the same orientation though).

[felix_666]

You may have tried this ...you can move the motor a bit, loosen off your mounts a bit give the engine a bit of a shake , you can usually pick up 5-10mm, but watch the fan -radiator clearance.Just a thought.

I've installed an e21 radiator, need all the space I can get.

I'm going to remove the d.s. and measure things, see what the difference is. I'm inclined to get it cut again so I don't have to deal with it later when I don't have the patience.