MXA 5R

**Bush65** · 12th April 2013, 05:00 PM

I just remembered you have a 4HE, not 4BD. Pretty sure the clutch for those is larger than 300mm, so the numbers I gave before (300mm clutch) will not suit.

I wouldn't be concerned about the diameter of the input shaft. The difference from the nominal size is probably for clearance - the spline for these is meant to locate on the tooth flanks not root/tip.

I don't have my book with standards for involute splines with me, or I would check. If you have a Machineries Handbook they have a section on involute splines with formulae and tables.

Edit: Unfortunately (depending on your point of view) my MXA-6 gearbox is bolted up to the engine and in the landie. C.h.e.i.f might not have fitted his box yet - he has been quiet on that front lately.

**Dougal** · 12th April 2013, 05:26 PM

I can't measure the shaft on my MSA. But my notes say 21 spline and 28.9mm. It was about 5 years ago, I would have measured it then, but I don't know if this measurement was shaft OD or clutch plate ID.

**Ancient Mariner** · 12th April 2013, 06:21 PM

Thanks to all will go with the 29mmx21 x 300 there are 2 flywheels available
for the 4he1 12"+13" both stepped as far as I can determine .The machinery
handbook covers involute splines in great depth from p 2047 to p 2069 Did`nt
think I would live long enough to wade thruit

thus the reason for the question

AM

**Dougal** · 12th April 2013, 07:03 PM

The last clutch plate I had out for measure-up was a Nissan. It was listed as a 25.4mm spline and that measured ~25.5mm inside the plate.

So that may answer your question. 29mm will be the clutch plate measurement, not the shaft measurement.

**c.h.i.e.f** · 12th April 2013, 07:13 PM

Unfortunately my box is mounted now so no help there however when I ordered my clutch disc I used the measurements that Bush65 gave me 29mm 21spline and asked if there was a match there was one that was close enough from memory may have been the same as Dougal just stated so I took the punt and thought close enough is good enough for the price

This may not apply for you as bush said your running a different motor that's not a B series but this is what I done...

Replaced original LR lt85/Isuzu bell housing with a truck 4bd1 bell housing.
Replaced spigot bush with 6203 bearing.
Kept original LR flywheel although it is not heavy enough (my new turbo choice may lower the vibrations compared to previously)
Kept std size (275mm) pressure plate as it was new and didn't require extra expense of a 300mm plate.
Ordered a 275mm friction disc to suit the mxa
New throw out bearing
Used lt85 slave cylinder but made new rod

**Ancient Mariner** · 2nd May 2013, 09:32 PM

New flywheel and clutch kit turned up today.The way they measure the plate
was what confused me [easely done]

the Exedy part number ISD 136U
300x28.9x21 spline the pressure plate is for the stepped flywheel so probably
not relevant here the release bearing number NSK 20DSD0210 .the pilot bearing a NSK 6203 However there was a bearing installed in the flywheel
a NSK 817-114 with the inner part of the race extended about 4mm either side
of the seal a better option if renewing the bearing if available as the ID-OD are
the same as the 6203
Excuse the crappy layout of the typing [ Computor illiterate]
AM

SheldonA · 5th May 2013, 07:44 AM

Perhaps should have this in a new thread... but if anyone is looking for measurements of differences between flywheels/clutches on N/A and turbo motors then I will have the two lying side by side shortly when I drop my 110 box.

I just dropped a box from behind a '93 model 4BD1 turbo truck motor.

It has the 300mm turbo clutch but was surprised to see it has the 24 spline 25mm dia. - not the later 21 spline 29mm.

Edit: Ah motor is '90, truck year is '93.... that's as expected then

**Bush65** · 5th May 2013, 09:38 AM

Originally Posted by the_grubb

Perhaps should have this in a new thread... but if anyone is looking for measurements of differences between flywheels/clutches on N/A and turbo motors then I will have the two lying side by side shortly when I drop my 110 box.

I just dropped a box from behind a '93 model 4BD1 turbo truck motor.

It has the 300mm turbo clutch but was surprised to see it has the 24 spline 25mm dia. - not the later 21 spline 29mm.

Edit: Ah motor is '90, truck year is '93.... that's as expected then

IIRC Ancient Mariner wasn't referring at all to a 4B engine, but to his 4H engine, so different flywheels altogether.