Vp ms4a. Ms4b

[Chalker]

Hi all
Can anyone tell me the difference between an MS4A and an MS4B gearbox?

Why could VP not be consistent, some bolts metric and some are Imperial!!! Some are 16mm spanner a some are 17mm for the same thread!!

Rent part over.

 

[pvb]

Can anyone tell me the difference between an MS4A and an MS4B gearbox?

Minimal differences, mainly bearings. I'm surprised any of the bolts are imperial.

 

[Chalker]

Thanks.

The rant was really aimed at my old MD31A engine, not the gearbox, although the Allen heads for bolts holding the water cooling pipes do not seem to be either!

 

[Trundlebug]

I have MD31A's too, and have noticed a bit of mix and match going on with metric and imperial fixings.

I think (but stand to be corrected) that Perkins actually assembled these engines in Peterborough.
Hence on the base engine things are imperial (the engine AFAIK isn't a derivative of anything else or used on anythings else, it was a purpose built marine engine)
Specific marinised / VP ancillaries are probably the metric stuff.

Just a rough guess at trying to explain the mixed bag.
Good engines though on the whole, very efficient, if a little noisy (that's because they are direct injection).

 

[scottie]

I have MD31A's too, and have noticed a bit of mix and match going on with metric and imperial fixings.

I think (but stand to be corrected) that Perkins actually assembled these engines in Peterborough.
Hence on the base engine things are imperial (the engine AFAIK isn't a derivative of anything else or used on anythings else, it was a purpose built marine engine)
Specific marinised / VP ancillaries are probably the metric stuff.

Just a rough guess at trying to explain the mixed bag.
Good engines though on the whole, very efficient, if a little noisy (that's because they are direct injection).

Nothing to do with Perkins all Volvo penta in house development although late starter may know more if Dieutz or Recardo had some input

 

[Chalker]

Good news today. My gearbox is fine but the damper plate/absorber is in many many pieces.

 

[STUART P]

The idea of using 2 different size spanners is you only need one spanner set and not 2 of every thing.

 

[oldgit]

Just a warning .......the internal differences between the MS4B and the MS5B are substantial .
The main vertical drive shaft and associated bearings are totally different sizes.
The width of the central oil channel in the shaft is not the same.

In all the exploded diagrams the later MS ie 4A and 4B gearboxes appear to be similar internally/externally but bits may also not be interchangeable