Thread: Isuzu MSA gearboxes

2nd and 3rd were Ok for a bit but notchy, then it got hard to get across to 4th 5th. Then I could get 4th but could not get into 5th so came home in 4th.
Took the top off but the selectors worked OK then. Sliding across and back and forth nicely off the box but when put back on still would not move far enough.
I have to look a bit further

Keith

Lying awake thinking about this the worse it gets.
With the gearbox and transfer boxes in neutral should not I be able to rotate some of the gears in the MSA.
Levering with a screwdriver on the edge of the box none want to turn.
Maybe the handbrake is jamming but thats too easy, with the T box in neutral that would not affect it would it?
It seems as if something has seized and as I have an adapter mating to the LT95 it may be there.
In the morning I will jack up a wheel and see if anything will turn. I dread taking out the box as the truck is too heavy for the 4 poster and it means crawling around under again. Getting to old for this.

Keith

Originally Posted by 123rover50

Lying awake thinking about this the worse it gets.
With the gearbox and transfer boxes in neutral should not I be able to rotate some of the gears in the MSA.

Sounds like you're trying to turn the motor over. You'll need someone to put their foot on the clutch.

Wonder if you've ended up with reverse and a forward gear engaged at the same time while the selecter was off.

Steve

What are first and reverse like for selection?

Minor note, I found that when the box is not being driven (engine off stationary vehicle) it is a bit notchy at first when working through all gears from reverse through 5th, however after a few attempts everything lines up inside the box and shifting through the sequence is smooth.

Chase up any other suspicions by all means, but maybe take the top off again and this time see if you can move the rings by hand. Probably obvious but make sure your selectors are lining up with the grooves.

Did this difficulty in changing come about after any event or maintenance or has it been gradual?

I posted a photo of the top off my gearbox on my RRC thread under the isuzu 4bd1 section if it helps (need a few more views to get it to 10,000 ).

All the gears on the shaft seem to have moved towards the front.
The big gear at the back now has about 10mm end play.
Perhaps this is why the selectors are not lining up and perhaps selecting two gears at once.
I have ordered a WSM from Isuzu . Have to buy the whole set just to get the MSA5G.
I have forgotten what holds it all together. Perhaps the big nut has come loose.
Looks like I will have to pull the Tbox anyway to see whats happening.
Another MSA 5G box I pulled the top off has bugger all end play in that big gear and the selector rings can be moved by hand 4th to 5th and back etc. On this box in the truck I cant, everything is tight.