Thread: Any MSA-5G gearbox experts out there?

I had the top off the gearbox some months ago. From memory the two bolts, marked 54, hold one of the shift mechanisms in place - so I would not touch those. All the other head bolts are in blind holes.

I would drop the front output shaft for clearance and give it another go. If the bolt is too rounded try a mini stilson or one of those sockets designed to bite into bolt heads or if a welder is handy a bit of steel extension.

You could also undo one of the sensor bolts and fill, but setting levels would be hit and miss.

I once had a situation of a steel bolt in a fragile aluminium housing. The bolt just wouldn't move and I did not want to break the alloy with excess force (tried heat etc). Ground down the bolt, then drilled the bolt to almost the same diameter, tapped it, and put in a slightly smaller bolt.

Not that I think it worth the effort, but you could braze a filler plug into the auxillary power take off cover. Come to think of it, I think the retaining bolts for the cover are open to the inside, providing a small fill hole.


IMGP3470.jpg

IMGP3471.jpg

I pulled 1 or 2 bolts out of the PTO, but no dice all were blind.

I removed front propshaft but still not enough room. Spent $60 at bunnings on some vise grips, i can get a good bite, but cant get it to budge even with a pipe for leverage. I tried welding but not enough clearance to get a decent weld.

And now im just munching the plug.

Thanks for the idea, I put out a request to a mate to see if he could help me weld a new filler plug to the PTO housing. Wish i did this on day 1 :P

Lets hope after all this that the oil is indeed the issue with hard shifting when warm :P.


While i have MSA/MSB/MXA people looking what oil are people using, the old oil smelt like VMX80 (Same as transfer box iirc) But the box itself says 5W-30;

Can you pump new oil in via the drain hole? Rubber or cork plug with hand pump line running through the centre. Overfill to 3 litres to account for loss as you do a quick swap from bung to bolt. Test drive to see if issue resolved. Not resolved, then box out for repair and tackle the filler bolt in comfort.

Buy yourself a set of these

Ive used mine for exactly the same problem numerous times

12pc Twist NUT Socket SET PRO Damaged Broken Bolt Remover Easy OUT Extractor | eBay

NB the ones above are just an example, think they only go to 21mm. Other brands go up to 24mm

I run vmx80 in mine, was much better than the 5w 30. And i just undid the drain plugs on both my msa5g and 5r with relative ease

Just give you all an update and hopefully closure :P,

So i tried some additional tools and basically due to lack of clearance the old filler plug is impossible to get out (transfer front shaft is right infornt of the filler plug). I thought long and hard about it and after workingonit 's comment I got a Oxygen sensor bung, you would normally weld onto exhaust pipes.



and called in a favour and got it mig welded onto the PTO cover. I measured where the old fill plug was from the bottom of the trans, and it worked out at about 5mm above the center line of the PTO panel.



Now with the PTO cover being thin metal and even with a cold rag onit, the MIGs heat warped the cover. I sat around with some wood and a rubber mallet and slowly straightened it out over the space of 45 minutes. But obviously it would never be 100% flush. So i grabbed some high temp gasket stuff.



I haven't used this before, but im a convert. You put it on thick-ish then put everything together finger tight, wait 1 hour, tighten fully then wait 24 hours.

Grabbed a standard sump plug that fit the 02 bung and filled and now were back on the road. And after about 2000kms the copper sealant hasnt leaked a drop, may even think about using it on the transfer case.

So all in all, looks as if the VMX80 has made it nicer to drive, and i flushed the hydraulic clutch 2 or 3 times, and checked the extension from the hydraulic piston to the clutch arm(?) it is now working well, I may need to revisit sooner or later just to try and re-adjust.


Thanks all

Possibly a bit late if you have covered 2000 plus kays since refilling the box, but the heavier 80 grade oil is not detrimental to the life of the gearbox is it?
The Perentie box takes engine oil and any heavy viscosity oils can be harmful. Maybe the recommended oil for the Isuzu box is for a similar reason.


Cheers, Mick.

Vmx80 is a manual transmission fluid. Its designed for gear boxes. Its not a gear oil like what goes in your diff. It's actually quite thin