exchange diffs
Moderators: rickf, raymond, Mr. Recovery
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- Staff Sergeant
- Posts: 123
- Joined: February 5th, 2014, 8:56 am
- Location: Brisbane Australia
exchange diffs
I have a noisy diff ,would you believe, but only in fourth gear under load. The diff man took it apart and said it was perfect, like new, so now I want to change over the front and rear diffs and see if that is any better. I read somewhere that they are interchangeable. Is that so and is there anything I should be aware of or just a straight IN-OUT- and on your way job. Does it help to add super thick oils like STP (do you have that). It looks like treacle. Col
Re: exchange diffs
yes, they are identical and a straight swap. we have STP, though i never put any in the differential. i tried as best as possible to follow the lube order to the letter. since yours is in good condition, it is possible that the rpm's are hitting a note that vibrates the sheet metal of the rear floor. i did an experiment once on mine, placing several heavy bags of sand on the rear floor, just to test this idea. with the sheet metal thus dampened, most noise went away. pity we can't drive around like that, eh?
Re: exchange diffs
I thought my gearbox had a problem in 4th as it also sang like a dieing diff.
As 3rd was really buggered i swapped the gearbox. The noise in 4th remains the same.
I then was leaning towards the diff but i have since decided its just a harmonic resonation that happens to manifest as the lower end of 4th gear.
Have now decided its just the nature of the beast.
If it was a normal car id turn the radio up..
As 3rd was really buggered i swapped the gearbox. The noise in 4th remains the same.
I then was leaning towards the diff but i have since decided its just a harmonic resonation that happens to manifest as the lower end of 4th gear.
Have now decided its just the nature of the beast.
If it was a normal car id turn the radio up..
Re: exchange diffs
These differentials are noisy to begin with. When I got my truck, it had 86 miles on the odometer and it was already noisy.
BTW, a worn transfer is also making a lot of noise. Both the needle bearing at the brake drum and the intermediate shaft make noise when worn. Noise in my truck did go down considerably after I overhauled the transfer. http://g838.org/viewtopic.php?f=3&t=9242
BTW, a worn transfer is also making a lot of noise. Both the needle bearing at the brake drum and the intermediate shaft make noise when worn. Noise in my truck did go down considerably after I overhauled the transfer. http://g838.org/viewtopic.php?f=3&t=9242
Horst
1972 USMC M151A2 w/ROPS (ex Barstow) and M416
1962 M201 and trailer
1966 GTO,1982 E350 Skoolie, 1987 SJ413, 1987 911
Gone: 2xM35A2c, Unimog 404S, Hanomag AL28, DKW Munga
1972 USMC M151A2 w/ROPS (ex Barstow) and M416
1962 M201 and trailer
1966 GTO,1982 E350 Skoolie, 1987 SJ413, 1987 911
Gone: 2xM35A2c, Unimog 404S, Hanomag AL28, DKW Munga
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- Staff Sergeant
- Posts: 123
- Joined: February 5th, 2014, 8:56 am
- Location: Brisbane Australia
Re: exchange diffs
Hmmmm, So if I load up some sand bags and install a car radio I'll be able to hear my wife nagging me about how noisey and bumpy my baby is ! Decisions decisions . Come on in Rick and Dan, you know everything.
I jacked up a rear wheel and ran it in top gear and used a stethoscope to listen to the rear end but no bad noises so I put the pick-up on the gearbox and it was quite a good even noise as I would expect. It's exasperating isn't it. Does anyone out there have a 151 that doesn't have the same problem.
I jacked up a rear wheel and ran it in top gear and used a stethoscope to listen to the rear end but no bad noises so I put the pick-up on the gearbox and it was quite a good even noise as I would expect. It's exasperating isn't it. Does anyone out there have a 151 that doesn't have the same problem.
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- Staff Sergeant
- Posts: 123
- Joined: February 5th, 2014, 8:56 am
- Location: Brisbane Australia
Re: exchange diffs
Nobby that's really disheartening what you wrote.
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- Sergeant Major
- Posts: 524
- Joined: June 6th, 2015, 7:39 am
- Location: Kuranda, Far North Queensland, Australia
Re: exchange diffs
Might be time to offer for sale a MUTT noise reduction kit: six sandbags and instructions
Howard
Howard
Howard
Daimler Ferret Mk 1/2
AM General M151A2
Austin Champ
Daimler Ferret Mk 1/2
AM General M151A2
Austin Champ
- raymond
- Major General
- Posts: 3428
- Joined: November 26th, 2007, 8:29 pm
- Location: God's country, Clarksville Mo.
Re: exchange diffs
A heavy mat on the rear floor goes a long way toward quieting the noise.
Raymond
"On the day when crime puts on the apparel of innocence, through a curious reversal peculiar to our age, it is innocence that is called on to justify itself." Albert Camus
"On the day when crime puts on the apparel of innocence, through a curious reversal peculiar to our age, it is innocence that is called on to justify itself." Albert Camus
Re: exchange diffs
step 1: get a sandbag step 2: place on rear floor step 3: repeat five more times step 4: put IPOD buds in ears step 5: ignore passengers screaming at you to slow down step 6: accept the fact that life is short, have fun.kmam wrote:Might be time to offer for sale a MUTT noise reduction kit: six sandbags and instructions
Howard
well, you said you wanted instructions. i copied this from the official us army manual. really. honest. would i lie?
Re: exchange diffs
Sorry Auzzie, Don't have a lot to offer. These are noisy little critters so you know. I had a diff go out on me, puked out a seal and ran dry before I even knew it so I was driving with no oil in it. It was glowing by the time I got home and it was screaming. I put in a rebuilt one I had and it was nice and quiet...................... for a couple weeks and right back to the usual noise. As has been said though the transfer case bearings can mimic the sound of the rear so you may have to look there also. And when you were listening to the rear did you only have one wheel in the air? That would not have been good in high gear! That would mean the tire in the air was spinning at roughly 120 MPH!!!!! That would be because the spiders in the rear would be doubling the speed of the one tire turning with the other stopped. Always jack up both sides and support under the outer ends of the control arms so that the axles are not drooping. You are not going to hear any noise from the rear when it is spinning with no load. Go down the road listening to the noise and then push in the clutch and pop it in neutral and shut it off while coasting at 50 MPH. Now listen for noises and see what you hear. If you have the military NDCC tires then that is most of the noise.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone
Re: exchange diffs
Good news.
Everything on mine was drained and refilled with decent oils over the winter.
Now that we are having summer in the uk I've been running the mutt as a daily toy and it seems to be quieting down nicely.
Perhaps there is hope
Everything on mine was drained and refilled with decent oils over the winter.
Now that we are having summer in the uk I've been running the mutt as a daily toy and it seems to be quieting down nicely.
Perhaps there is hope
Re: exchange diffs
I cut a horse stall mat to fit the rear floor and it helped a lot.
Pray for our Wolf Hunters.
Re: exchange diffs
Three 45 pound sand bags in the bed made mine a pleasure to drive. It no longer sounds like the rear diff will shortly self destruct and it improves the ride. I bought some military sand bags and they look like they belong there.
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- Sergeant First Class
- Posts: 267
- Joined: January 8th, 2011, 9:03 pm
Re: exchange diffs
As an experiment i put new seals in the diffs on my a-1 and re installed the yokes with new sealant and rubber mounted the diffs with heavy rubber 3/8" thick above the diff and a heavy rubber washer above the mounting nut and steel washer so the diffs were sandwiched in. I feel it made quite a difference in reducing the harmonic vibes that previously occurred. I just thought i would try it as an experiment, I have 4 mutts ,three a-2's one a-1 and the only one that kinda howled was the a-1. All quiet now.
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- Sergeant First Class
- Posts: 267
- Joined: January 8th, 2011, 9:03 pm
Re: exchange diffs
You should also check to make sure the rear motor mounts have not compressed to the point that the transmission is resting on the crossmember as that will transmit a lot of noise also. Happened to me....changed to new motor and tranny mounts and quieted things quite a bit.