Changing Diff Fluid What do I need to notice
04-25-2007, 10:52 PM
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Changing Diff Fluid What do I need to notice
I already did the search but I need some advice that I didn't see in any of the posts. I'm getting ready to do this tomorrow. Here is what I know and here is what I want to know
11.5 takes 4 Litres of 75 90 or 140
9.25 takes 3 Litres of 75 90
I have a batch of Cenpeco full syn ready to go in.
What do I look for with regards to wear or wear patterns with the ring gear and pinion?
What is the bolt torque specs?
Thanks for the help.
11.5 takes 4 Litres of 75 90 or 140
9.25 takes 3 Litres of 75 90
I have a batch of Cenpeco full syn ready to go in.
What do I look for with regards to wear or wear patterns with the ring gear and pinion?
What is the bolt torque specs?
Thanks for the help.
04-25-2007, 11:00 PM
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kerry, wear patterns on gears should be centered both top to bottom and side to side on the teeth. if you look really closely at the shiny wear surface, there should not be any pitting, flaking, small lines in any direction. nothing but smooth shiny wear. there shouldn't be any raised metal, or metal that looks like it is being pushed or rolled in any direction. no discoloration(blueing)
basically if it looks bad, it is.
basically if it looks bad, it is.
04-25-2007, 11:17 PM
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If the gearset isn't making noise, there's no metal particles suspended in the oil, and you don't find any chunks in the bottom of the pumpkin - you're good to go.
04-26-2007, 06:04 AM
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Thanks Guys, Last time I changed the Diff Fluid, I didn't even look ... bigger fish to fry .... so this time I thought I'd give it a good check. Last time I torqued to 25ft/lb with never seize on the threads. I'm heading out now to do it ... so I hope the "never" part worked. I thought that bluish look was my redneck heat treating process.
04-26-2007, 01:56 PM
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I have a bad habit of overtightening small bolts so its good to have a bench mark. In everything else in my life "good nuff" applies....my truck gets a little better care. ks
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04-26-2007, 11:34 PM
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I'm planning on doing mine this weeekend. Gonna use the Royal Purple. The truck has 78k on it not sure when it was done last. I might go ahead and do the tranny too. First time i've ever serviced a diff. Dosen't sound to hard tho.
04-27-2007, 12:25 AM
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I just did mine today along with an oil change and filter, and replaced the front brakes with EBC "yellow stuff" brake pads
The ring and pinion looked great! I was scared to do it only because this is the first time it's been done, 39K plus on the original oil
Surprisingly the oil looked pretty good. Brownish but no foaming and no metal suspended in it. While I was at it I sanded off the cheap flaking paint on the diff cover, primed it and hit with a coat or two of high heat engine paint. While that was drying I cleaned the diff with brake cleaner and wiped everything up real good inside. Filled it with Redline 75w/140. Surprisingly the brakes work and there ain't no leaks from any of the changed fluids I'd have to say that it was a very productive day and it feels good to know that it was done correctly and it was done by me!
The ring and pinion looked great! I was scared to do it only because this is the first time it's been done, 39K plus on the original oil Surprisingly the oil looked pretty good. Brownish but no foaming and no metal suspended in it. While I was at it I sanded off the cheap flaking paint on the diff cover, primed it and hit with a coat or two of high heat engine paint. While that was drying I cleaned the diff with brake cleaner and wiped everything up real good inside. Filled it with Redline 75w/140. Surprisingly the brakes work and there ain't no leaks from any of the changed fluids I'd have to say that it was a very productive day and it feels good to know that it was done correctly and it was done by me!
04-27-2007, 05:38 AM
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Cool, this is a timely thread as I'm thinking this weekend is a good
time to change the diffs. I'm changing the oil and probably the transmission and transfer case also.
Probably overkill as the beast only has 5K miles on her, but after it's done I know everything is right (type and grade fluid, amount, etc) and as others have mentioned, I can check for debris in the drained fluids!
Cheers
time to change the diffs. I'm changing the oil and probably the transmission and transfer case also.
Probably overkill as the beast only has 5K miles on her, but after it's done I know everything is right (type and grade fluid, amount, etc) and as others have mentioned, I can check for debris in the drained fluids!
Cheers
04-27-2007, 09:08 AM
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Just an FYI, Royal Purple does not make ATF+4 transmission fluid for Dodge trucks.
04-27-2007, 03:03 PM
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I just did my rear diff, I used amsoil 75-140, bolts are torc, to 30ft pounds, did mine to 15 each then back over them in a criss cross patern to 30, pretty easy to do.
04-30-2007, 12:20 PM
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On the scale of 1 to 10 in hardness of things I've had to do to my truck this is a 1. The cover is rusted to crap and the bolt heads were rusted to crap but the never seize as usual did its job and the bolts unsnapped with modest torque with no chance of a broken bolt. The fluid was not much worse than when it went in ....no metal anywhere and the magnet had a light dusting of powder. I put 75/90 in last time so I decided on 75/140 thinking there would be some wear....it looks what I imagine it would look like when new....shiny and smooth with all the machine marks in tact. 15 minutes to remove the bolts and cover, 45 minutes to coax the cold 75/140 in that little hole, 15 minutes to never seize and reinstall the bolts. I tightened all the bolts by hand until they were snug then went around corner to corner and torqued the till they were 25ft-lb. If your thinking of doing this do it. Have a big funnel with a flexible spout. Unload your bulk oil into 1 Litre containers as dumping it from a 7.5Litre jug is a PIA....I'll check them when I'm back under later on today to replace the other 2 u-joints....The first ujoint was seized solid in one direction....bearings were half their normal length....grease in one half ....lacking grease in the other half....when greasing ....grease until it comes out from all four dust shields.
