Over the last few years many individuals & companies have appeared on sites like Ebay selling uprated bearing kits for the M32 gearbox.
However has anyone actually stopped to ask themselves, 'What makes them uprated and how is it going to help me?" Well hopefully we can clear a few things up for you below and show you actual solutions that are available to you.
Lets start this off by going into detail about the M32 'UPRATED BEARINGS' that we constantly hear about and that are being sold all over the internet. These suppliers often have no experience in rebuilding gearboxes what so ever and simply sell parts as uprated to increase their sales, which as we will explain is false advertising!
There are two suppliers that produce the taper roller bearings in the size that is required for the end case of the M32.
In the original M32 unit produced from 2004 onwards, Timken bearings were fitted throughout the gearbox. Then from around 2009 onwards M32 units came with either SNR or Timken bearings from the manufacturer, however there was no clear logic to the crossover as you would have some 2011 model vehicles with Timken and other earlier vehicles with SNR. We can only assume the variations in bearing choice came down to production dates of the particular unit at the factory. Both the SNR and Timken bearings are the same dimension, however the SNR should be able to handle a slightly higher radial force due to the pitch of the rollers compared to the Timken which seems to be set up more for thrust load. Even though there is a very slight difference in the set up, both bearings will and do fail on a regular basis.
It is worth noting that we repair just as many M32 units with SNR bearings as we do Timken. Both brands are extremely good quality, so it is certainly not an issue with manufacturing standards.
The manufacturer of the gearbox itself have realised that the issue with this unit is not down to what brand of bearing they use, but the underlying problem of lubrication to the bearings as well as the physical size of them.
2. See The Difference?
M32 Standard End Bearings. The SNR on the right is often sold as uprated, however as you can see they are exactly the same except a plastic guide cage.
M32 standard SNR end bearing. As you can see it suffers the exact same wear as the Timken. This bearing is at the beginning stage of wear and shows heavy pitting in the centre of the rollers.
M32 standard Timken end bearing. This bearing is a lot further into the wearing process. You can see in this picture the physical dimensions of the rollers has change results in substantial movement in the guide cage.
3. The Solution.
An updated and improved design of the end casing has been released with a few noticable modifications.
Here we have two M32 end cases, the one on the right is the early version and the one on the left is the new modified version. as you can see from the photo on the left the case has a oil feed to the output shaft end bearing that passes through the input shaft end bearing this helps with bearing oil lubrication and then prevents bearing failure. Compared to the older style case which its main cause of failure was oil starvation.
The new modified end cases now seem to be fitted as standard from factory on M32 units. We have seen some vehicles from 2012 onwards with this upgrade, but again there is a crossover were old design of units are still finding their way onto newer vehicles. You can see on the old style of case were the end bearing has failed. We have highlighted the oil feed on the new modified case which means better lubrication for the end bearing of the input and output shafts. So in conclusion, having larger bearings, as well as an oil feed to the bearings themselves, is a clear attempt by the manufacturer to rectify a common fault with the previous set-up. To date with the 800+ M32 units that we have repaired, we have not seen a model with new end case come in with bearing issues or failure. This means installing a new modified end case is a no-brainer.
Original end case bearing shell.
This photo shows the bearing shell for the new modified end casing. As you can see the outer diameter is 62mm which is 7mm larger than the original bearing shell of 55mm. Bigger bearings means higher load ratings.
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