Rear axle question

[btoscano]

I have read about the rear axle a few times and still am not clear about the problems for parts availability. I read that the 3. 07's were custom build to Dodge specs.



The truck is relatively new to me & when I changed the rear axle oil, it was black. It didn't smell too bad. I used Redline 80w-140. (This is not a LSD diff). Then I checked it the next month. It was black too. In the two small parts that don't drain, I ran my finger against the housing and it came out shiny. I kept doing this & kept getting a shiny finger. Eventually I got it all out. I refilled with Redline GL-5 80w-140.



The pinion looked fine and intact. But the spider grears (on the end of the axle shafts) had some black lines.



Every once and a while when I start off turning left from a stop, I hear a noise.



This is my first pick-up & first vehicle with a solid rear axle.



I am wondering if I will have a problem fixing this? What exactly will I have a problem sourcing parts for?



Right now I'm aware I might need to rebuild at some point but so far it still runs, and I don't hear anything howling.



Thanks,

 

[RobbieH]

Are you sure the noise is coming from the rear, and can you describe it?

 

[bgilbert]

80-140 is pretty heavy, only recommended if you tow and run heavy most of the time. If you are hearing noise when turning, try adding some ' FRICTION MODIFIER ' aka LSD additive to it. It can't hurt your open diff. If you have compressed air, you can use brake cleaner to get all of the old gear oil out when you do a diff service. I usually use at least two can of brake cleaner, then blow it dry with compressed air.

Cant really help you and your last questions of sourcing parts.

Bill

 

[1stgen4evr]

Rear Axle

If you have 3:07, you must have and 89 or 90 with 727 automatic. The 3:07 is indeed a rare aminal. Do whatever is required to find the metal that is showing up. If you lose the differential you are down for the count. You will be able to find a rear axle but it will only be here in the classified. There are no new parts. You can of course go to a different ratio but that will also require a housing. A complete axle. The parts don't interchange. The closest ratio is the 3:54 and you will then need an OD transmission to slow the engine at highway speeds.



Bill is right about using something to cut the lube when cleaning but when I am dealing with metal fragments (shinny finger) I am never satisfied as to the cleaning unless I totally dissasemble and immaculately clean everything. Now I know that's a big chore. But the fragments will get into the bearings and seriously degrade the life. Probably already have.



Bottom line is that if you have fragments, you have something coming apart.



Feel free to PM if you have other questions.



1stgen4evr

James

 

[btoscano]

Yes, its a 1990 D250 w/ the 727. About 145Kmi.



Where should I look for the metal to be coming from ?



The big pinion gear looked "fine" & I don't hear any howling going down the road.



I searched on car-part.com and found a few listed but they were all about $1000 and far away from Tennessee.



I wouldn't mind the OD transmission of course, but I think I'd need to get the driveshaft shortened to get the 518 ? Sounds like more work than its worth or am I mistaken?

 

[cerberusiam]

If your hearing noise when turning it is probably wear in the spider gears, pin, and bushings. The fine silver stuff is the bushings wearing down. You really need to drop center section and pull the pinion and look at all the bearings and check for pitting and/or wear. By the time the ring gear is showing evidence of problems a lot of other things are pooched so don't rely on visual examination to tell you there is an issue. Unless it used some odd bearings a rebuild will probably run around $250 with bearings and a spider kit. The bearings will need to be pressed on and off the 3rd member and pinion and if your lucky using the old shims should put you close to being good. Backlash in the pinion is critical on these rears so pay attention to it. Given a mechanic not looking to get rich on every job you can have the rear rebuilt and setup for around $500 and be good for another 150k. Once you start spinning bearings and races and chewing up the pinion and ring gear things get real expensive real quick.



The trans is problematic, either you stay with what you have and rebuild it or upgrade to a newer unit. Given the cost and durability you are better off going to the 47RH rather than the 518 and get the benefits of newer technology. Its a spendy route and requires so modifications but the results are well worth it.



As far as the cost goes its a personal choice. Some would say $5k is not too much while others would not spend $500. Good luck.

 

[btoscano]

I don't have a problem spending $500 if it'd last. I'm concerned about whenI should spend this $500 and if anyone can recommend someplace around Nashville to 'do it right' ? I have seen local 'legendary' MB mechanics skip a LOT of steps when putting things back together. I'm not sure how they get away with it - either they are very good or the customers just dont' drive enough for problems to show up.



I don't think I want to rebuild the entire drivetrain rear of the engine. This is only a 2 wheel drive! I'd like to have a 4x4 instead, but this works right now.

 

[Philip]

If you are thinking of outsourcing the work on the rear axle. Look for a shop that does a lot of medium sized truck repair. A lot of the small local shops will not have experience in this type of repair.



Like everyone has stated. If you are seeing a lot of shiney flakes in the gear oil. Get it loooked at. In my experience on the model 60 & 70 rear axles around 150k is the time to do a bearing replacement.



With your being a 3:07 rear it would be expensive to rebuild. Dodge is the only place to get the 3:07 gears. I checked into getting a new set of gears on time. No one had a listed other than Dodge.

If you have 3:07, you must have and 89 or 90 with 727 automatic

The 3:07 was used up to 93 model year. You just see very few with the 3:07 above 91. 5. My 93 has 3:07's from the factory.

found a few listed but they were all about $1000

I wish I could have found one that cheap when I had to replace my rear axle on account of a bent housing. Dodge does not have any 3:07 housing in stock any more. They also do not have any complete axle assy's in stock eather. At that time there were 4 back orders for housings. Dodge did not make another run of parts happen.

 

[rowland]

As far as O/D trannys go, putting in a 518 is almost a bolt up job. Especially in the 2x4 where you don't have the t-case to worry about. You need to run a manual switch for the overdrive and shorten the driveshaft, otherwise no big deal. The hard part is finding one at a reasonable price.



Isaac

 

[1stgen4evr]

Shims bearings and such

My experience is that if the bearing shoulders are not damaged, new bearings will put everything back in the factory setup position. Otherwise, seting a ring and pinion is not for the novice. Take it to a highly qualified shop. I will not be on the computer for a week or so. I would be happy to give other info but it will have to be later. I would not reccomend driving the truck much before repairs are made.



I would also guess the spider is the source of trouble.



James

 

[btoscano]

Thanks for the commnets. I've asked local TDR members for shop recommendations.



Thanks,