Gearbox replacement

[gle240]

Hey,

My 84' 240 B23A has bad noises from the gearbox.
Sounds like bearing noise which appears mostly on 1st and 2nd gears. On 3rd it still exist but with less noise, and disappearing on the 4th. The 5th gear sounds OK.

I guess that this is a M47 gearbox. From looking at the side of the gearbox it says 1023561, which looks like a P/N, but I couldn't locate it in the parts catalog.

I have a few questions:
1. How to tell which gearbox is installed on my vehicle? (The VIN says M47 BTW)
2. Which other manual gearbox may fit this car without and major changes?
3. Any recommendations about overhauling? how difficult it can be?
4. is there any recommended place to buy an overhauled gearbox?

Thanks.

[Clan]

Originally Posted by gle240

Hey,

My 84' 240 B23A has bad noises from the gearbox.
Sounds like bearing noise which appears mostly on 1st and 2nd gears. On 3rd it still exist but with less noise, and disappearing on the 4th. The 5th gear sounds OK.

I guess that this is a M47 gearbox. From looking at the side of the gearbox it says 1023561, which looks like a P/N, but I couldn't locate it in the parts catalog.

I have a few questions:
1. How to tell which gearbox is installed on my vehicle? (The VIN says M47 BTW)
2. Which other manual gearbox may fit this car without and major changes?
3. Any recommendations about overhauling? how difficult it can be?
4. is there any recommended place to buy an overhauled gearbox?

Thanks.

One of the ball bearing races worn , its a good old fashioned gearbox so fairly easy to dismantle if you have done it before , a bearing is reasonably priced too . You need to diagnose which bearing before hand then you know what to look for . so basically it needs a pair of hands , some know how and a £20 bearing or two .

[Bugjam1999]

Go to this link, type 'M47' in the search bar and click on the first document that comes up, that'll give you some idea of the work involved to rebuild it.

https://ozvolvo.org/archive/

It'd be worth checking if your car has a cable drive for the speedo or a later electronic speedo with a sensor on the back axle - if it's the later type then a replacement M47 to fit it will be very cheap. If it's got a speedo drive then those gearboxes are much harder to find and more expensive if you can find one, so it might be cost effective to rebuild it.

Cheers

[mentepazza]

if I was to replace the box I would replace it to M46+ overdrive. The 5th gear overdrive ratio it’s lower compared to the M47 5th gear and at motorway speed you get lower rpm compared to M47 box. Saves you some noise and petrol (I guess just a little).

[gle240]

Thanks for the replies.
As far as I understand, it is M47 gearbox. the speedometer is cable driven.

I've looked at the overhaul manual and it seems complicated, but not impossible.
I just need to get my hands on all replacement parts before disassembly of the gearbox.

Is there a kit for overhaul or should I just collect it one by one?

[Nicholas Lewin]

Sorry - I replied to your wants thread first...

I had many months of trouble with an M47 gearbox a while back. So far as I can gather overhaul kits are no longer available and the two transmission specialists I went to just weren't interested - however try Skandix and GCP who carry a limited number of the bearings/synchro rings and so on

The advice re M46 + overdrive is sound altho' not so easy to find (don't forget that 740s can give up M47 and M46/o/d boxes - not just 240 s. They are exactly the same

It will depend on what is actually wrong with your box as to whether you can source spares. dare I ask, you have checked the oil level and the oil type?

Lastly, and in the end just what I did, sourcing a s/h box (whichever type) is relatively straightforward, changing the oil whilst off the car is dead simple and replacing the gearbox is a fairly straightforward job - much more so than overhauling the internals of a 'box

Good luck and keep us posted!

[Bugjam1999]

^careful- an m46 or m47 from a 740 won’t have a speedo drive, which the OP needs.

However depending on what is broken, a late, low mileage M47 with no speedo drive ‘might’ be a good source of spares if no new parts can be found, but of course it depends what is broken in the OPs gearbox.

Cheers

[gle240]

BTW - how about the oil type?
I understand it's an issue for M47 transmissions. ATF type F is recommended in the red book by Haynes and other places, but what if it's a high-mileage gearbox?

Actually, where I live is quite hard to find the ATF-Type-F and I'm looking for a replacement.
Any recommendations?

[Nicholas Lewin]

ATF it is - Red Line Racing do just the job and it transformed the box I had fitted to the car

What are you calling high mileage?

[gle240]

380,000 Km until now.
Is it only ATF type F? So hard to locate this type here.