Ok I'm an absolute moron.. I CANNOT figure out how to post, this is the best I could do... So sorry if I'm in the wrong area. But I have an 05, 1500, 5.7 Hemi with the 4.25. I am having vibes that I'm spent a buttload on trying to fix. Long story short I traced it to the rear diff. Brand new driveshaft AND u-joints. It is at it's worst between 45-60mph, but if you floor it from a stop it will do it at 25-30 then stop. The pinion had a very slight amount of play, not a whole lot. I know that isn't right.. but could that in itself cause said vibration? Has new wheel bearings too. It's doesn't do it while turning, it doesn't keep getting worse and worse the higher the speed. So I'm thinking pinion bearings are just shot? I've already spent $1100 and will be $1500 if I rebuild the rear end bearings.. PLEASE advise if anyone has any experience with this.. Thanks. Oh from the old driveshaft to the completely rebuilt one there was ZERO CHANGE in the speed at which it vibrates, or the intensity. Also vibes get less intense after about 60 so it cannot be a bent axle. Also no grunting/rumbling like bad gear alignment. Backlash in also within spec. Obviously the pinion was moving a bit, but not too crazy although as I said I know it should be no play (and by play I mean up, down, all around). I just don't wanna keep dumping money into the thing if there's some kind of defect with the rear differentialTOk I'm an absolute moron.. I CANNOT figure out how to post. So sorry if I'm hijacking this thread. I have an 05, 1500, 5.7 Hemi with the 4.25. I am having vibes that I'm spent a buttload on trying to fix. Long story short I traced it to the rear diff. Brand new driveshaft AND u-joints. It is at it's worst between 45-60mph, but if you floor it from a stop it will do it at 25-30 then stop. The pinion had a very slight amount of play, not a whole lot. I know that isn't right.. but could that in itself cause said vibration? Has new wheel bearings too. It's doesn't do it while turning, it doesn't keep getting worse and worse the higher the speed. So I'm thinking pinion bearings are just shot? I've already spent $1100 and will be $1500 if I rebuild the rear end bearings.. PLEASE advise if anyone has any experience with this.. Thanks. Oh from the old driveshaft to the completely rebuilt one there was ZERO CHANGE in the speed at which it vibrates, or the intensity. Backlash is within spec, it's not the axles because when you past 60 miles per hour it calms down, by play I mean up down all around.. But there's no clunking or popping... just vibes.

 

Sorry about the repeat.. my tablet is being stupid

 

You actually want to be in the third gen section. I'll move this thread there for ya.

If your pinion bearing is sloppy, you need to address that FIRST. There should be a bit of rotational slop, but, absolutely nothing in any other direction.

 

Ok Thanks... was hoping to get some feedback by now.. but I guess no one has had the same issue

 

 

Not really any howl.. just the vibes. It had a little howl at highway speed. I am now in the process of rebuildING the bearings in the diff cuz they were not very good. The pinion also had play. I have rebuilt driveshaft and new u-joints as well. Brand new tires on all 4. Brand new CV axles. Brand new wheel bearings. Brand new motor mounts. I know it's in the rear diff for the most part. I guess I'll find out after I get it back together. I will update if I still have troubles I guess...

 

Oh and the gears were set correctly besides the pinion moving all around. So I'm sure that allowing the driveshaft to move around was a good chunk of the vibes.. but it also did it when I took it around the block with the rear shaft out.. that was the weird thing. But b4 tearing the rear diff apart, to make sure that was it I removed the CV shafts and the front driveshaft which made no difference. So I know it's something wrong with the rear. The Backlash was good too it was just the pinion play.. I'm really hoping that is it! I don't want to lose all the money I have in it!

 

I'd put my $$ on the pinion slop being the problem. That's a huge amount of input torque being allowed to essentially flop around. Even if it is just a little.

If it were me, I'd pop the cover, and do an inspection of the oil that comes out, and then do a pattern check on the ring and pinion. A little more backlash than spec isn't as likely to cause the bad vibes, but rather the up/down all around play that the pinion has.

If the mesh looks good, you might get away with double checking the torque on the pinion itself. It's kind of a pain to get it torqued properly, and if someone was already in there goofing around, it might not be correct. .

 

Nope... I decided to redo all the bearings in the rear. Took all the play out, and although it helped the intensity quite a bit, it did NOTHING to the actual problem! So it's definitely between the transfer case''s bad bearing, and the slip yoke or something! The driveshaft was re-tubed, new front end put on it, and new u-joints! Cannot friggin believe this! I am about to cut my losses! Only thing I can think of is the bearing(s) in the transfer case. But, I think it is the input shaft one that is bad not the ouput. I won't know for sure until I get it open.. but I am sick of blindly replacing parts! Although I now know for sure it's the driveshaft, but I know it cannot be the shaft itself, unless it's either the slip yoke, or the rear flange. I just want that Damn problem to STOP so I can finally start fixing the stuff that need to be fixed up to be nice such as new headlight lenses, a new windshield, shocks, and upper ball joints/control arms. I sure hope it's that bearing in the t-case.. idk... What do you think about that? When I had the front shafts in, the only thing that would make it stop when punching the gas would be if it was in 4wd!

 

What t-case do you have in your truck?

Have you checked runout on the rear axles? (a slightly bent axle would be fun to find.....)