Complete axle w/ 3:55 gears, questions

FoxMustangLvr

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Oct 14, 2012
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I see for sale a complete drum to drum axle with 3:55's, 4 lug drum brakes. It is removed from a 88 5.0 Mustang and sitting aside. Guy is asking $300 for it. I know a set of gears plus install is about a $600-$800 value and i'm wanting to save some $ so guys i need some tips.

What do I look for when inspecting the axle? He's offering to remove the cover, besides verifying that it says 3:55 what should I be looking for visually?

Thanks,
Matt
 
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if he has the fluid in it still see if it smells burnt and how much material is in the fluid. also id lok at the spider gears close to see if any of them are chipped.
 
$300 is on the high range for a drum brake rear axle. setup. I see them all the time for 2-300. The problem is you don't know if you are buying a 40000 or 200000 mile rear end, or why it was taken out- was it an upgrade to discs brakes or because the posi unit is bad, leaking or twisted axles, noisy gears, etc. Think of your average 5.0 owner and what they do to these cars over 20 years vs. what you already know about your car.

Like what was said, pull the cover off. Smell the fluid, look for chipped gears, shavings from the clutch packs or shims. Bring some playdo or clay and put some on the ring gear and run the gears to see the contact patch. You want to see it deep and in the middle of the ring gear. Also make sure the housing/axle tubes aren't cracked or rusted out.

If you plan on using the brake hardware- are you planning on transferring over your brake shoes, springs, drums? Does it come with the E brake cable, brake lines/hoses?

Pull off the drums and inspect the wheel cylinders for leaks - I would replace them anyway now that they are off the car
Look for any fluid on the shoes
Inspect the drums for scoring, cracks, warpage
make sure all mounting tabs are intact
Inspect the pinion flange area for leaks and that it turns proper

If you can

Pull the C clips off and pull out the axles. Inspect the bearings and seals.
inspect the axles themselves for cracks. It will be hard to tell if they are twisted from abuse.

At a minimum, I would install new brake cylinders, new axle seals, if your rear brake pads, springs and drums are good transfer them over, and clean and refill the rear end with fluid and friction modifier, and a new set of U joints. The right way would be to install all new brake hardware- cylinders, springs, pads and turn either turn one of the set of drums or new drums if they are not in spec, and new axle seals and bearings. No sense having to pull everything apart twice. You can get most of the parts from Autozone, Rock Auto, LRMS, etc.

So IMO to do it right will cost more than $300. Probably another $100 or so for parts but assuming everything else is good you'll be all set.

While you are at it, inspect your UCA and LCA bushings, rear shocks, etc. Again, no sense having to take stuff apart twice.
 
$300 is on the high range for a drum brake rear axle. setup. I see them all the time for 2-300. The problem is you don't know if you are buying a 40000 or 200000 mile rear end, or why it was taken out- was it an upgrade to discs brakes or because the posi unit is bad, leaking or twisted axles, noisy gears, etc. Think of your average 5.0 owner and what they do to these cars over 20 years vs. what you already know about your car.

mikestang63 pretty much said it all. I bought a rear axle from a guy before Christmas last year. It works fine but has noisy gears, and when I asked him about it he said he never noticed the noise because he had dumps on his car. Things like this you'll never be able to tell from inspection so there is some inherent risk with buying a complete axle like this.
 
Are there some gear sets to avoid? This guy pulled the axle off another car and has never used it and was told it has 3:55's but will pull the cover in front of me to inspect and verify. I would use any parts that look good and transfer over anything that isn't good. I am however getting scared out of the deal the more I think about it. Too many unknowns and a lot of work to be out of nearly $300. If this guy had it in his own vehicle and could tell me it's good from experience then I'd feel better about it. I don't want noisy gears like Boost has and even worse would hate to have any clunking or clicking around turns

Thanks guys
 
For $300 I think it's a bit steep. I paid $175 for my complete axle with 3.73's and 4-lug drum brakes (even though I replaced them). If you can get him down it might be worth it, but for $300 I would probably pass.
 
if he has the fluid in it still see if it smells burnt.....

Friction modifier is always gonna smell burnt, no matter how many miles are on it. That stuff just plain stinks!

I agree with inspecting the gears though. Checking for chips and proper wear pattern is a good start. See if the trac-loc is still functioning too. look for leaks and/or wear around the axle seals. A little in and out play in the axles is normal, but anything more than 3/8" of an inch or so cold indicate a problem.

His $300 is a good start, but isn't a great deal for a rear end with drum brakes. I'd offer him less and if anything is amiss with the above, I'd either offer him a lot less, or keep on looking.

Gear noise could indicate an issue, but then again, it might not. I've had gears set up to spec in the past and still had them make a little noise on the highway. Some gears just do. The used 3.73's in my Couple "howl" a little on the highway and they're bang on spec. They just tend to wear that way over time. I'm sure it's amplified by my aluminum driveshaft, but they otherwise perform flawlessly. Not much to be done about it but change out to another set of gears? :shrug:
 
Friction modifier is always gonna smell burnt, no matter how many miles are on it. That stuff just plain stinks!

I agree with inspecting the gears though. Checking for chips and proper wear pattern is a good start. See if the trac-loc is still functioning too. look for leaks and/or wear around the axle seals. A little in and out play in the axles is normal, but anything more than 3/8" of an inch or so cold indicate a problem.

His $300 is a good start, but isn't a great deal for a rear end with drum brakes. I'd offer him less and if anything is amiss with the above, I'd either offer him a lot less, or keep on looking.

Gear noise could indicate an issue, but then again, it might not. I've had gears set up to spec in the past and still had them make a little noise on the highway. Some gears just do. The used 3.73's in my Couple "howl" a little on the highway and they're bang on spec. They just tend to wear that way over time. I'm sure it's amplified by my aluminum driveshaft, but they otherwise perform flawlessly. Not much to be done about it but change out to another set of gears? :shrug:

When you set up your gears where did you check the pattern? Used gears can only be patterned on the coast side since there is typically much less wear as compared to the drive side. Its been my experience that even used gears should be quite. The only gears I've ever seen make noise in matter what are Richmond's and who knows maybe that's just me.
 
The problem I see in this case is the rear end in question doesn't even belong to a car the guy the OP is looking to buy from. The person who owns it now bought it off someone else, so who knows what the deal is. The OP is buying the rear third hand at this point and if something fails, I guarantee you the guy he buys it from will say, "hey, I told you I bought it from someone else" Once the OP buys it, it's his problem.

IMO I would only consider buying a used rear from the person who owned the part and can tell me everything about it and why it was removed. Otherwise, that needs to play into the negotiation of the price and the expectation that you will need to change out seals, bearings, etc.
 
When you set up your gears where did you check the pattern? Used gears can only be patterned on the coast side since there is typically much less wear as compared to the drive side. Its been my experience that even used gears should be quite. The only gears I've ever seen make noise in matter what are Richmond's and who knows maybe that's just me.

I'm really not sure how they were set up, as I did not install them. The person who did however is one of the better tech's at our local dealership and trusted friend. He's done two other rear ends for me in the past...both of which have performed flawlessly. I may ask him next time I see him to take another look at them.
 
It seems to me after a lot of reading that even if you take a brand new gear set to a reputable person there is a chance there may be gear noise even if everything is to spec. Seems like a gamble either way and I'd rather risk less money and get gear whine instead of big money for the same result. However I'm still not wanting to buy and complete rear end from somebody that isn't from the person that ran it on their vehicle.

Has anyone hear payed for brand new gears to get installed only to get a whine/howl? What did you do? Did the mechanic blame the gear set? The gear mf'r blame the mechanic?
 
Just keep your eyes open.
Rear ends are one of those parts that if you are patient, they will come at a great price.
I got a 9" Granada rear (very hard to find and expensive) for $75 at the salvage yard by just keeping my eyes open.
I also got a 3.55 Trac-Lok 8.8" with disc brakes, from a Thunderbird, for $100 off Craigslist.
It's in my GT right now.

As far as wear and noisy gears, you just need to go with your gut.
If the unit makes any noise when you spin it by hand, it will be 100x louder when driving.
There can be a little slop rotationally in the gears, but NONE in any other direction.
Also, make sure it has visible clutches inside the diff. A rear that has changed hands several times (or a dishonest 1st time seller) can be called 'limited slip' (Posi, Trac-Lok, pick your term), but actually be an open diff, and if you don't look, you won't know.
 
Just keep your eyes open.
Rear ends are one of those parts that if you are patient, they will come at a great price.
I got a 9" Granada rear (very hard to find and expensive) for $75 at the salvage yard by just keeping my eyes open.
I also got a 3.55 Trac-Lok 8.8" with disc brakes, from a Thunderbird, for $100 off Craigslist.
It's in my GT right now.

As far as wear and noisy gears, you just need to go with your gut.
If the unit makes any noise when you spin it by hand, it will be 100x louder when driving.
There can be a little slop rotationally in the gears, but NONE in any other direction.
Also, make sure it has visible clutches inside the diff. A rear that has changed hands several times (or a dishonest 1st time seller) can be called 'limited slip' (Posi, Trac-Lok, pick your term), but actually be an open diff, and if you don't look, you won't know.

Ratio, I have an 8.8 disc setup that I bought a while back that sat out open to the weather. When I try to turn it, it won't turn at all. What do you think I should do to inspect it for future use - BTW, some of the oil leaked out as well... I already have a ProAuburn that I was considering install in it. I'd like to use this unit for my disc conversion soon.

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Mikestang63,

What do you think as well? Still planing to end up at Specialties with it for the gear and guts install...
 
Ratio, I have an 8.8 disc setup that I bought a while back that sat out open to the weather. When I try to turn it, it won't turn at all. What do you think I should do to inspect it for future use - BTW, some of the oil leaked out as well... I already have a ProAuburn that I was considering install in it. I'd like to use this unit for my disc conversion soon.

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Mikestang63,

What do you think as well? Still planing to end up at Specialties with it for the gear and guts install...

Sound like it needs to be torn down, cleaned, lubricated and all the rusty and worn parts replaced. I would spray everything down with PB blaster and let it sit for a day or two then try and turn the axles and pinion. pray the whole thing isnt siezed up.
 
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I have an 8.8 disc setup that I bought a while back that sat out open to the weather. When I try to turn it, it won't turn at all. What do you think I should do to inspect it for future use - BTW, some of the oil leaked out as well... I already have a ProAuburn that I was considering install in it. I'd like to use this unit for my disc conversion soon.

If I am reading this right, you have an entire rear, that still probably has 'some' oil left in it... ???

If so, I would just look at the brakes being locked up.
Rear ends are very tough. Tough enough to survive in the weather as long as the cover is on and there is some oil in them.
If you pull it apart, and there is some rust, it's fine as long as the rust hasn't pitted anything, at least in my opinion.
 
Ratio,

I haven't even opened the pumkin. It's sitting in my back yard right now. The brake stuff I took off when I got it and they are fine because I took them off early. I was the one who left this unit outside thinking the same thing: Rearends are tough! they can take the weather. i bought it some years back for my future disc swap, and you know how that can go OR NOT GO!

It did rust on the outside abit bust a light sandblast and that's gone.

I guess I will just open it up a nd see what inside.

Sound like it needs to be torn down, cleaned, lubricated and all the rusty and worn parts replaced. I would spray everything down with PB blaster and let it sit for a day or two then try and turn the axles and pinion. pray the whole thing isnt siezed up.

Yikes! The thought.... I believe I paid $450 for the whole setup back then. Hate to loose it all. Going out to spray it now!!! It's my day off so I got to get it done.

Trying to use this day for research and questioning.

Thanks guys, alot!