Differential Ring Gear Pattern

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Hi Guys, I dont have a Jeep but I need some help if someone is willing please. There are no forums I can find for my truck. I have a 1997 Mitsubishi Canter 6 tonne tipper and I have replaced the pinion and carrier bearings in the diff.

I needed to add a 2 thou shim on the pinion because the preload was too tight (these have a non crush sleeve type spacer). Before I put new bearings on the pinion I honed out the old ones so I could easily slip them on and off to try out different shim thicknesses. The spacer/shim is between the pinion head and bearing, so it difficult to take the new one off each time to try shims.

The original contact pattern was terrible, drive side near the toe and triangular or some of them dome shape (sunset as they say) I didn't have the correct size shim for under the pinion head so I cut one down to fit the shaft.
It was about 10 thou, about I/2 the original shim( 20 thou) under the pinion. This didn't seem to make much difference where the drive side contact pattern is.

I thought maybe just putting in the new bearings would get the pattern a lot closer to original ( original shim now put in).

These are pictures I have of my contact pattern. The coast side looks ok but I assume the drive side is too deep and close to the toe. I adjusted the backlash between the min/max specs at 8 thou to 12-14 thou.
there is a slight difference of the pattern coming in from the toe (two lots of drive pictures) but it is triangular and I am assuming is too deep in the tooth, and too near the toe. therefore from all the patterns I see on the internet I must, increase the pinion depth (lessen the shim thickness). Is there anyone who can help with an educated guess as to what shim size I should try. I dont want to keep taking this bearing on a number of times and off as its easy to damage.

Final comments, this pinion and ring gear still has meat on it, but it could be worn unevenly and giving me a bad tooth contact. Bearing preloads are correct on pinion and carrier, and backlash I adjusted a few times. Runout is just within spec of the manual at 4 thou. I put pressure on the ring gear as I turned the pinion.
Thanks, any advice will be helpful.

 

[hosejockey61]

Hi Guys, I dont have a Jeep but I need some help if someone is willing please. There are no forums I can find for my truck. I have a 1997 Mitsubishi Canter 6 tonne tipper and I have replaced the pinion and carrier bearings in the diff.

I needed to add a 2 thou shim on the pinion because the preload was too tight (these have a non crush sleeve type spacer). Before I put new bearings on the pinion I honed out the old ones so I could easily slip them on and off to try out different shim thicknesses. The spacer/shim is between the pinion head and bearing, so it difficult to take the new one off each time to try shims.

The original contact pattern was terrible, drive side near the toe and triangular or some of them dome shape (sunset as they say) I didn't have the correct size shim for under the pinion head so I cut one down to fit the shaft.
It was about 10 thou, about I/2 the original shim( 20 thou) under the pinion. This didn't seem to make much difference where the drive side contact pattern is.

I thought maybe just putting in the new bearings would get the pattern a lot closer to original ( original shim now put in).

These are pictures I have of my contact pattern. The coast side looks ok but I assume the drive side is too deep and close to the toe. I adjusted the backlash between the min/max specs at 8 thou to 12-14 thou.
there is a slight difference of the pattern coming in from the toe (two lots of drive pictures) but it is triangular and I am assuming is too deep in the tooth, and too near the toe. therefore from all the patterns I see on the internet I must, increase the pinion depth (lessen the shim thickness). Is there anyone who can help with an educated guess as to what shim size I should try. I dont want to keep taking this bearing on a number of times and off as its easy to damage.

Final comments, this pinion and ring gear still has meat on it, but it could be worn unevenly and giving me a bad tooth contact. Bearing preloads are correct on pinion and carrier, and backlash I adjusted a few times. Runout is just within spec of the manual at 4 thou. I put pressure on the ring gear as I turned the pinion.
Thanks, any advice will be helpful.

My understanding from reading your post:

• The gears are original (used)
• You were just changing out the bearings?

If that's the case, then you don't set them up like new gears. I check backlash and run a pattern BEFORE disassembly to see what it looks like. If all you are doing is changing bearings, then there shouldn't need to be any adjustments as it would put everything back in the original place when new. Gears work harden, so you can't "reset" used gears to new gear specs. If I were you, I would install the new bearings and then place all the shims, and/or whatever was in there, back in their original locations. If you added the pinion pre-load spacer, then I would put the pre-load to about 15 thou.

 

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Thanks for your input, I appreciate your time in answering me. The reason I didn't do a pattern check before I pulled it apart was some ring gear bolts had started to come loose. I noticed the truck had become noisy when decelerationg so I stopped driving and stripped it down. To my shock some bolts had come completely out and the ring gear was loose. Fortunately they hadn't damaged the ring gear or pinion teeth. I had this truck for 6 years, I wouldn't have driven it many miles, I mainly just use it to landscape on my property, however I would have put 20,000 miles or more on it in short runs to town.
Someone must not have put red loctite on the carrier bolts or done them up with enough torque is all I can think. Your answer makes sense. The only change I made, are the bearings and I did need to put a 1.92 thou shim (.05mm metric we use here) on the spacer sleeve. I did this because one of the old bearings felt it was binding as i tried to set the pinion preload. So I bought new ones and the preload was definately too tight when I installed them and started to tighten up the pinion nut. With the small shim put in the preload tangential torque went nicely to spec.
Thanks again for your advice I will put the diff in and give it a run.

 

[Eyeswideopen]

Thanks for your input, I appreciate your time in answering me. The reason I didn't do a pattern check before I pulled it apart was some ring gear bolts had started to come loose. I noticed the truck had become noisy when decelerationg so I stopped driving and stripped it down. To my shock some bolts had come completely out and the ring gear was loose. Fortunately they hadn't damaged the ring gear or pinion teeth. I had this truck for 6 years, I wouldn't have driven it many miles, I mainly just use it to landscape on my property, however I would have put 20,000 miles or more on it in short runs to town.
Someone must not have put red loctite on the carrier bolts or done them up with enough torque is all I can think. Your answer makes sense. The only change I made, are the bearings and I did need to put a 1.92 thou shim (.05mm metric we use here) on the spacer sleeve. I did this because one of the old bearings felt it was binding as i tried to set the pinion preload. So I bought new ones and the preload was definately too tight when I installed them and started to tighten up the pinion nut. With the small shim put in the preload tangential torque went nicely to spec.
Thanks again for your advice I will put the diff in and give it a run.

Thanks for your input, I appreciate your time in answering me. The reason I didn't do a pattern check before I pulled it apart was some ring gear bolts had started to come loose. I noticed the truck had become noisy when decelerationg so I stopped driving and stripped it down. To my shock some bolts had come completely out and the ring gear was loose. Fortunately they hadn't damaged the ring gear or pinion teeth. I had this truck for 6 years, I wouldn't have driven it many miles, I mainly just use it to landscape on my property, however I would have put 20,000 miles or more on it in short runs to town.
Someone must not have put red loctite on the carrier bolts or done them up with enough torque is all I can think. Your answer makes sense. The only change I made, are the bearings and I did need to put a 1.92 thou shim (.05mm metric we use here) on the spacer sleeve. I did this because one of the old bearings felt it was binding as i tried to set the pinion preload. So I bought new ones and the preload was definately too tight when I installed them and started to tighten up the pinion nut. With the small shim put in the preload tangential torque went nicely to spec.
Thanks again for your advice I will put the diff in and give it a run.

Thanks for your input, I appreciate your time in answering me. The reason I didn't do a pattern check before I pulled it apart was some ring gear bolts had started to come loose. I noticed the truck had become noisy when decelerationg so I stopped driving and stripped it down. To my shock some bolts had come completely out and the ring gear was loose. Fortunately they hadn't damaged the ring gear or pinion teeth. I had this truck for 6 years, I wouldn't have driven it many miles, I mainly just use it to landscape on my property, however I would have put 20,000 miles or more on it in short runs to town.
Someone must not have put red loctite on the carrier bolts or done them up with enough torque is all I can think. Your answer makes sense. The only change I made, are the bearings and I did need to put a 1.92 thou shim (.05mm metric we use here) on the spacer sleeve. I did this because one of the old bearings felt it was binding as i tried to set the pinion preload. So I bought new ones and the preload was definately too tight when I installed them and started to tighten up the pinion nut. With the small shim put in the preload tangential torque went nicely to spec.
Thanks again for your advice I will put the diff in and give it a run.

Hosejockey61 I am not 100% sure what you meant with what you ended saying "I would put the preload to about 15 thou" did you mean because I needed to ad a 1.92 thou spacer between bearings to get the correct pinion preload which I now have. did you mean to reduce the shim under the pinion head and bearing to 15 thou? This would increase pinon depth ( ie decreasing its depth in to the ring gear). Or did you meant tangential torque at 15 inch lbs. Or instead were you trying to say leave everything and adjust the backlash at 15 thou? Sorry, just wanted to be clear what you were saying. Thanks

 

[hosejockey61]

I was referring to the actual pinion pre-load. Leave everything else the same. If you have your pinion pre-load where it needs to be, then disregard my statement.

 

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I was referring to the actual pinion pre-load. Leave everything else the same. If you have your pinion pre-load where it needs to be, then disregard my statement.

Thanks, i was hoping you meant that. Pinion preload specs are between 1.4 and 2.2 ft lbs. I have it somewhere in the middle between 1.8 -2 ft lbs. Fortunately carrier preload is set with adjusters instead of shims which make sit easier. Pinion preload has to be done first and installed before this can be done, as you would know. You have been very helpful hosejockey61 and saved me a lot of time chasing my tail.

 

[Rickyd]

Picture of this truck?

Looks like you have a flip top cab?

 

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Picture of this truck?

Looks like you have a flip top cab?

Yes its a Mitsubishi Fuso (canter) 1997 model. Basically the same as this but an older model. The local councils use them around here for small road work jobs and mini excavator work. 6300GVM holds about 4 ton.

 

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GVM is in kilograms. Metric system in Australia. Cheers

 

[Rickyd]

I've driven a few Isuzu npr and nqr trucks. Not fast by any means but good rigs. It does take some getting used to sitting on the front tires

 

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I've driven a few Isuzu npr and nqr trucks. Not fast by any means but good rigs. It does take some getting used to sitting on the front tires

Yes I am 67 with a bad back, I know what you mean. Its been very reliable up until now.
It gives a better ride with a load full of sand or gravel. Hardly ever need to use first, very low geared. When the diff went in it, a mechanic told me I could install a lower ratio diff and it will give me a better top end road speed. I couldn't find anything so I decided to do the repair on this one.