Iain_U1250
Explorer
Quick up date:
I am replacing the gears in the portal axles with new high speed gear sets - this will enable me to drive at 100kph @ 2200rpm. After stripping the left hand portal, the bearings all looked fine so I had planned on just putting in the new gears and saving myself the $1600 or so for new bearings.
On stripping the right hand side I discovered that the bearings were very close to total failure - see the photos below.
TO cut a long story short, the mechanic who had worked on the truck previously, had fitted normal "Industrial" strength ball bearings - however, the load rating on them is about half of the "heavy duty" bearings that MB specify. The result was that the those bearings had worn out, and contaminated the large outer roller bearing resulting in them wearing as well. Checking the left hand side I found that they had replaced the bearings on that side with "normal" bearings as well - so I have decided to replace all the bearings.
I tried to get the "heavy duty" bearings form my local bearing places - and after much searching came up blank - they just could not get exaxtly the same specification bearings - they came close, but consulting a bearing book and reading all the number on the bearing, the closest they could come to is about 80% of what was required. In the end I got the bearings from a UK Unimog dealer in nice MB boxes at around the same price as the "normal" bearings from Australia - I also found out that MB have upgraded the ball bearing in the upper gear to a roller bearing - checking the bearing books again - the roller bearing has about 20% more capacity than the original bearing and more than 75% more capacity than standard industrial bearing.
In the end I all I have left from the original portals are the casings, the wear rings and the bolts - I have new gear sets, bearings and seals, so that should be good for another 100,000km or so :smiley_drive:
I am replacing the gears in the portal axles with new high speed gear sets - this will enable me to drive at 100kph @ 2200rpm. After stripping the left hand portal, the bearings all looked fine so I had planned on just putting in the new gears and saving myself the $1600 or so for new bearings.
On stripping the right hand side I discovered that the bearings were very close to total failure - see the photos below.
TO cut a long story short, the mechanic who had worked on the truck previously, had fitted normal "Industrial" strength ball bearings - however, the load rating on them is about half of the "heavy duty" bearings that MB specify. The result was that the those bearings had worn out, and contaminated the large outer roller bearing resulting in them wearing as well. Checking the left hand side I found that they had replaced the bearings on that side with "normal" bearings as well - so I have decided to replace all the bearings.
I tried to get the "heavy duty" bearings form my local bearing places - and after much searching came up blank - they just could not get exaxtly the same specification bearings - they came close, but consulting a bearing book and reading all the number on the bearing, the closest they could come to is about 80% of what was required. In the end I got the bearings from a UK Unimog dealer in nice MB boxes at around the same price as the "normal" bearings from Australia - I also found out that MB have upgraded the ball bearing in the upper gear to a roller bearing - checking the bearing books again - the roller bearing has about 20% more capacity than the original bearing and more than 75% more capacity than standard industrial bearing.
In the end I all I have left from the original portals are the casings, the wear rings and the bolts - I have new gear sets, bearings and seals, so that should be good for another 100,000km or so :smiley_drive:
