Rampage MT center differential gears binding - Help Please

G-Man

G-Man

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I am having serious binding issues with the two gears in my center diff. Here is how it started. I noticed the center drive shaft drive cup going to the front diff was loose and lost a set screw. So I ordered after market cups with the stainless sleeves pressed on etc. I installed the new cups and reinstalled the assembly back in the truck. Now it is binding bad when I bolt the two center diff mounts down to secure it. I have yet to buy the aluminum mounts and still use the plastic ones BTW. So I then started thinking it had something to do with the new cups. I have another new center diff assembly with all stock parts and it still binds after tightening it down completely. I have had this diff in and out probably ten times now with different combinations. I am so frustrated with this thing it is sickening!! I have tried moving the shims behind the bearings in the mounts, I put two shims in one side then tried the other,I tried just one shim on one mount, I tried a shim in each mount and ALL have done the same thing. I have the teeth on the crown gear facing the rear of the vehicle and I have the mounts installed with the wider side facing down. Pretty sure I have the install correct . Hopefully somebody else has had a similar issue that can enlighten me on the subject before I make it an RC molotov coctail...
 
G-Man

G-Man

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I have the aluminum mounts coming for tomorrow. Gonna give them a try. If anything it will strengthen the diff up some. I guess none of you have had any similar issues???
 
G-Man

G-Man

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I am having serious binding issues with the two gears in my center diff. Here is how it started. I noticed the center drive shaft drive cup going to the front diff was loose and lost a set screw. So I ordered after market cups with the stainless sleeves pressed on etc. I installed the new cups and reinstalled the assembly back in the truck. Now it is binding bad when I bolt the two center diff mounts down to secure it. I have yet to buy the aluminum mounts and still use the plastic ones BTW. So I then started thinking it had something to do with the new cups. I have another new center diff assembly with all stock parts and it still binds after tightening it down completely. I have had this diff in and out probably ten times now with different combinations. I am so frustrated with this thing it is sickening!! I have tried moving the shims behind the bearings in the mounts' date=' I put two shims in one side then tried the other,I tried just one shim on one mount, I tried a shim in each mount and ALL have done the same thing. I have the teeth on the crown gear facing the rear of the vehicle and I have the mounts installed with the wider side facing down. Pretty sure I have the install correct . Hopefully somebody else has had a similar issue that can enlighten me on the subject before I make it an RC molotov coctail... [/quote']Those center dogbone cups with the sleeve pressed on them, two of the four bind on the dogbones and one of the diff outdrive cups I got, the sleeve fell off when installing. I would have been bent if it would have came off when driving. Makes me wonder about the rest of the cups. All the labor tearing it down etc..
 
G-Man

G-Man

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Ya that helps alot thank you. I am wondering if something is bent to make it bind the gears. I may pull the input/brake pinion shaft out and look closely at it if these aluminum center diff mounts I just got don''t help. What I did is took the tranny gears off except the input shaft to center diff, then left the dogbones out of the center diff. When I spin the input shaft to center diff it is rather difficult to turn and the gears sound like a roulette wheel at a fair but worse.
 
G-Man

G-Man

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Well I am into this further than I expected. I also noticed the nuts holding on two of the transmission gears were coming loose. I removed the nuts and used loctite to reinstall. This now made the binding worse. I am guessing all the shafts got bent from all the loose parts.
 
G-Man

G-Man

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Not sure what the brake adjuster screws are. But I did check the set screws in the brake shaft connector. The set screws were intact and shafts were like glued in from factory. I am going to replace all the shafts and gears. I ran two tanks through it yesterday.
 
Phill

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On the gear side mount you will see 2 small grub screws , one top and one bottom that are used for adjusting the brakes.

Back em out a little and see if it makes any difference.

Your brake shoes should be loose enough to rattle when not applied
 
G-Man

G-Man

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Ya the brakes already rattle now. I think the pinion is either bent a little or the teeth are chewed up. I haven't had a chance to pull the brake assembly apart yet. Wish I could figure out how to post a video of how loud the mesh noise is between the input pinion and center diff gear.
 
G-Man

G-Man

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Well I finally got the time to tear the transmission gear plate off with the brake assembly. I now see that the gear shaft going into the brake assembly is bent a little. I can see it when I spin it. I am also getting a bearing noise out of it. I ordered a kit of bearings from Boca which should be here Monday along with all the other parts. The bearing kit doesn't include the gear plate bearings which I ordered separately. I am excited to get this thing back to running right again..
 
I

ika

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Center diff mount have up/down direction, gear must be down ti chassis, there is special cut on chassis - gear to sit down.
 
G-Man

G-Man

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Center diff mount have up/down direction' date=' gear must be down ti chassis, there is special cut on chassis - gear to sit down. [/quote']Ya I realize the center diff mounts are offset. I install it with the wider side down. With the dogbone installed the shaft is level. With the mount installed thin side down the shaft is too low leaning down on the center diff side. I see the cutout in the chassis you are talking about for the gear. Am I correct with saying the wider side down on the center diff mounts? I called Redcat. I swore that's the way they said it goes. He had to go to an actual MT to look and see cos the schematic is unclear even to him.
 
G-Man

G-Man

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Ok thanks for clearing that up. Because I didn't realize the hole for the bearings in the mounts were not centered when I tore it apart. Now when I put it back together tomorrow I will be sure it is in correctly. Thanks man!!
 
G-Man

G-Man

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New input pinion and lay shafts. New bearings throughout the gear plate. No more binding. But there is a little in and out play in the brake assembly making the pinion to center diff walk in and out a little. May have to shim the pinion to bearing a hair.
 
Phill

Phill

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New input pinion and lay shafts. New bearings throughout the gear plate. No more binding. But there is a little in and out play in the brake assembly making the pinion to center diff walk in and out a little. May have to shim the pinion to bearing a hair.
A little movement there is normal

Just as long as it's meshing OK
 
G-Man

G-Man

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A little movement there is normal

Just as long as it's meshing OK
Thanks Phill you have been a great help!! The movement is not severe just a little. The mesh seems better when I push in on the shaft. If I pull out it isn't as good but still not bad. There really isn't anything that holds that in place. May just leave it be if a little play is ok. I did shim the clutch drum though. It was enough to bother me.
 
Petrolheadz100

Petrolheadz100

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Hiw did the truck tun after the bearings install? Could it have been a bad bearing?
 

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