1990 marathon rear differential parts

[cincinnati_kid]

Gearboxes is what I do for a living and if we are replacing one member we either replace the mating member or we skim grind (with a CNC gear grinder) the mate to ensure a proper tooth form. You would not need to replace the entire gear set just the mating pinion to the final drive gear. Will it work by just putting a gear in it and that's it? Sure but you take a chance of not getting good contact against the worn pinion which could lead to premature failure. How did the gear break? Did something get in the mesh?

[smullins94]

Cincinnati-kid: thank you for taking time to talk through this. The gear broke when the retaining bracket worked itself loose (part 47 from the breakout i posted earlier). I am trying to decide on salvaging a part from a local cart junk pile or order a new one online. The new part is made by nevil. The new part specs a gear ratio of 15 to 1 the old part spec is 14.76 to 1. You think they are the same and just rounded up? The price diffence is $275 for new or $50 for old.

Madoc- do you think an elecric motor would use the same gear as a gas?

The cart is stock with a great paint job. No mods at all. I like the original shape.

[cincinnati_kid]

I would say for $50 I would throw a used one on and it should be ok. I wish there was a good way you could check the contact pattern without taking the whole rear end apart. You want the contact to be in the center and on the pitch line which is about halfway down the tooth. Gears wear into each other that's why its best to replace in sets but if you can get one for $50 I would do it. As for the ratio as long as the # of teeth is the same you will be fine. They probably rounded up.

[1989Marathon]

Cincinnati-kid: What brand of gear cutters/grinders are you using?

[madoc1]

Originally Posted by smullins94

Cincinnati-kid: thank you for taking time to talk through this. The gear broke when the retaining bracket worked itself loose (part 47 from the breakout i posted earlier). I am trying to decide on salvaging a part from a local cart junk pile or order a new one online. The new part is made by nevil. The new part specs a gear ratio of 15 to 1 the old part spec is 14.76 to 1. You think they are the same and just rounded up? The price diffence is $275 for new or $50 for old.

Madoc- do you think an elecric motor would use the same gear as a gas?

The cart is stock with a great paint job. No mods at all. I like the original shape.

yes i think some do. refer to the sponsors site i mentioned .

[cincinnati_kid]

Originally Posted by 1989Marathon

Cincinnati-kid: What brand of gear cutters/grinders are you using?

We have many cutters but our newest is a gleason and our primary grinders we have one gleason and 2 hoflers with our big hofler we can grind gears up to 102" OD and 60" face. We do gears from 4" OD to the 102" OD

[1989Marathon]

Originally Posted by cincinnati_kid

We have many cutters but our newest is a gleason and our primary grinders we have one gleason and 2 hoflers with our big hofler we can grind gears up to 102" OD and 60" face. We do gears from 4" OD to the 102" OD

That's petty cool. I am a controls software engineer for Gleason. What model machines do you have?

[smullins94]

THANK YOU ALL FOR THE HELP!!!!!

I went to a local cart shop here in Richmond VA (j early woods) and dug through 2 rear ends before matching up the gear. It came off an electric cart... go figure... the gas and electric rear gear is the same sometimes. The first rear I opened had a smaller gear. guess i got lucky. Cost me $30.

Everything was tight and no play. Cleaned all the parts...lots of gear grease...some 75-90 weight gear oil and she is closed back up.

Safe carting!!!