Difficult Shifting with Aftermarket Gland Nut?!

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 · 12 Jul 2012, 5:38 am

#912235

Some aftermarket gland nuts have their pilot bearing
installed too close to the outside.

This means that the input shaft can bind on it.

Thus it can never entirely disengage from the engine
when the clutch is operated.

Symptoms are difficult shifting,
and eventual deterioration of the synchros,
which have to work very hard to select the gears.

Even worse,
it can push the whole main shaft forward
and wear the nose cone,
then 4th gear can move out of gear
and machine itself into the intermediate housing.

Or even worse,
engine thrust bearing and shims can be over heated by the load,
eventually burning or spinning the bearing
due to the oil not being able to flow through to the thrust face.

Here are the tell tale signs:

In this case,
the main shaft bearing was pushing hard onto the nose cone. Luckily a steel thrust plate in this instance,
protected the magnesium nose cone:

Simple solution is to replace the Gland nut with something better, or machine it so the bearing sits deeper, by about 3mm.

In this case the trans was due for disassembly and inspection, so the input shaft was machined to clear.

westi wrote:That's mad Alan.

matberry Moderator Go hard or go home

8,114 posts · joined Mar 2006 · 12 Jul 2012, 8:54 am

#912241

Yes Dave, as usual, you are ONTO IT 👍 Thanks for your diagnosis and repair. Dave called it before the trans and engine were even split from each other. Mileage in this case is 51 000 km before the issue raised it's head in the form of 1st and 2nd synchro's giving up and making shifting difficult.

I do wonder though, the input shaft on type 2 tranny's is screwed into the mainshaft and locked into position by sliding the splined collar over the top. Was the M6 thread close to being all the way home as this will effect the overall shaft length.

I will be using Gene Berg gland nuts from now on....they fit without issues. Shame the performance aftermarket manufacturers rarely seem to get it right.

Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE

Ldog Commited Dubber

70 posts · joined May 2011 · 12 Jul 2012, 12:01 pm

#912263

Thanks for sharing I have Recently had this problem !!! 😢

1915,c95,44's,44x37.5,NA, DuBwAy

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 · 13 Jul 2012, 1:45 pm

#912417

matberry wrote:.

I do wonder though, the input shaft on type 2 tranny's is screwed into the mainshaft and locked into position by sliding the splined collar over the top. Was the M6 thread close to being all the way home as this will effect the overall shaft length.

For correct assembly,
the join where the M7 stud connects the shafts
is backed off a spline or two
to ensure the stud is unstressed.
This equates to less than 0.25mm.
Once it is fitted
the length can not change unless the stud strips
or is not installed correctly.
In this case everything was correct.

westi wrote:That's mad Alan.

matberry Moderator Go hard or go home

8,114 posts · joined Mar 2006 · 13 Jul 2012, 2:04 pm

#912420

Cool, I figured it would have been but needed to ask. I too instal with the M7 (ok I got that one incorrect...🙂 ) backed a spline or two, but my point is it could effectively lengthen the shaft so does need attention with this issue in mind.
Thanks DB

Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE

66brm Seriously Crusin Dubber

140 posts · joined Nov 2009 · 19 Jul 2012, 2:12 pm

#913385

Dave, can you tell us which non original glandnuts are causing the issue? I was going to use a CM glandnut in my current build but will toss it if its even suspect.

Perhaps the first letter of the companies name will suffice

66brm

vassy66T1 Wow ... are U reading this?

2,120 posts · joined Jun 2003 · 19 Jul 2012, 5:29 pm

#913410

It was a Scat but when Matt took it off (the gland nut) for inspection, the spigot bearing could be pressed home another 3mm 🙅

Check this upon purchase of a gland nut and the issue may exist no longer ??
Interested to hear from DB if this was the same with the other one or more he is aware of.

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 · 20 Jul 2012, 5:14 am

#913478

Hi Marcus,
in the other couple of instances I have seen
there was no room to press it in further.
The bearing had to be removed and the hole machined deeper,
or just a different brand fitted that was correct.

westi wrote:That's mad Alan.

vassy66T1 Wow ... are U reading this?

2,120 posts · joined Jun 2003 · 20 Jul 2012, 8:17 am

#913480

Thanks Dave

I was interested to hear what had happened in the other instances.
Gearbox is smooth as now 👍😁