Differential repair or replacement?

The quote was $1600.00 for a repair using a rebuilt differential and $2200.00 if they rebuild mine. If they rebuild it I get a year warranty. It only takes 3.5 hrs to remove and replace it not including this main part of the differential assy they gonna deal with see below and it only cost $350.00 Its a bad deal if it was me I'll make an about face and run like a speeding bullet and never ever see this guy again. Its your decision sorry this is all I got

Just found out that pinion gear is missing a tooth and spiders have some damage to gears. Ring gear looks good. What is the most cost effective way of getting repairs made? Shop that I went to can't make repairs, but told me best course of action would be to replace whole rear with used one, which they can do. Can vehicle be safely driven as is? Only symptom is feeling like you're driving on a washboard when car creeps forward in drive at idle. Otherwise no other symptoms at higher speed. Should I consider going to a transmission shop for repairs? Thanks in advance for your help.

First of all, if the pinion gear is missing a tooth then the ring gear is damaged and/or must be replaced. Ring and pinion gears are a set - you CANNOT interchange them..Even if the ring gear was ok (which I doubt) it must be changed...Damage to both pinion and spider gears indicates that pieces of debris were floating around in the rear..It will be more cost effective to replace the entire unit as compaired to repairing it..The only question is what is your price range -- a junk yard unit will have some miles on it -- call for prices. A new unit will run around $600.00- with zero miles on it and a warranty..
It is not smart or safe to drive this vehicle with a damaged pinion gear and spider gears...The rear WILL eventually sieze and explode. This could cause transmission - transfer case - and engine damage...

Thanks for your quick response! It has been most informative. Shop that did work guesstimated cost of junkyard unit to be in $500.00 range. Sounds like I need to be looking for different shop. They knew of damage but failed to tell me about it. They had done other work to vehicle, new brake lines, two new tires and new diff cover because old one rusted thru and was leaking. I returned a week later when my wife who drives vehicle daily told me about symptoms. A mechanic in shop told me about what they had previously found, but nothing was documented and no one told me previously. They also told me it would be okay to drive car until they could work up estimate. Where can I find new rear for $600 range. Would it be a complete unit or parts to rebuild ? Also I am new to the forum and had already contributed upon asking my initial posting. Thank you once again for your help!!!!

The $600 is just an estimate and is for just the parts required for a new rear (labor will be more)..If you want to purchase the unit yourself you must know what the gear ratio is, what size the differential is, and how many splines there are on the axle. It is most likely an 8.5 inch rear but you should go to the drivetrain specialists web site. There you can see what is involved with identifying what rear you have..You can also purchase everything you need there...You must also decide what type of traction you want - limited slip or posi..If installing a new unit, I suggest going with a Trutrack with the new stock gear ratio ring -n- pinion and a timken bearing installation kit....If you do not know how to install this init I suggest having a professional do it. DTS has instructions, but if you don't know what you are doing you can easily mess it up...Once again, driving this blazer will lead to more damage ..
BTW - be aware when purchasing a new ring -n- pinion gear set..There are different manufacturers. O.E.M. is the quietest gear set and I suggest O.E.M. But if you are planning on going off roading and stuff like that then Richmond - U.S Strange - AAM gears are what you want..Motive Gears are junk...

Can I use the rear end pinion of a two door 2001 four wheel drive Blazer
on a 1999 four wheel drive four door Blazer?

Yes if the gear ratios are the same and they bolt up.Please let us know if you need anything else to get the problem fixed.

If you mean swapping the entire rear axle, as long as the ratio, ring gear size and the brakes are the same it should be OK. Be sure the 2 door isn't a ZR2 option as those are wider and use different mounts than the "common" versions.

If you mean just swapping the actual pinion itself, no. You would want to replace both the ring and pinion so they will wear in as a set.

Would it be possible to engage my 4x4 drive, remove the damaged gears from the rear end and run effectively in front wheel drive with zero torque being transfered to the rear wheels? This would also include the rear end being oiled and sealed so the seals don't go dry and cause extra wear. I know it is probably not the optimum work around but would it work short term as i get the money and parts together.

Removing the rear shaft to prevent torque transfer to rear differential can work but the rear differential would still be turning when the rear wheels are turning. You cannot remove the rear differential as the shafts needs the differential bearings to hold them in position so the correct answer is no, except for moving the vehicle around for parking etc but not long distance or high speed drivings.

Hi, my car just started making hard noises when i'm at speeds 40-50mph. I took the car to firestone and they recommended, i take the car to an axle shop, related to the rear end noises. My friend who is a mechanic but not certified, took me to auto salvage yard and recommended that i take a rear-end off a 1998 chevy blazer. My question is two-fold my car is a 1997 chevy blazer is it okay to use a 1998 rear-end. My other question is i only have one car and i need it to go to work until Monday, can i continue to drive the car for work. Are there safety concerns

Ok as for the rear end working the wrecking yard has books to tell them that, I beleive it will work fine. Now what you need to know to make sure it will work is have the needed info. Now you need to know what rear end you have weather is is a 7.5 or a 7.62 and what gear ratio you have like is it a 3.73 or 4.10 or ? If you don't know or don't have a tag on the rear end to give you the needed info then call your local GM dealer and give them the last 8 of the vin and they can tell you. As for driving it can't tell you I have no idea what it sounds like how loud it is and so on. Therefore I can't answer that question.

I need to have my front dif re-built, The problem is that it needs to be shipped out and its gonna take a few weeks. Can i still drive the truck without the front axles being bolted into the bearing hub assemblies, or will the bearings fall apart. If not can i cut a pair of junk axles and put the spline shaft end thru the bearing assembly and bolt it in? will this work.

No and No. If you put an axle in place, there is no way to keep it from moving around in the (empty ) differential.

The differential would not be there. the whole outer case assembly will be removed. i have to ship it out as a whole, not just the inside. And what I mean by putting the axles back in is cut the axle off at the first knuckle so i could bolt that piece of the axle back to the wheel bearing assembly. pretty much destroying a set of axles.
i just need to know if i drive away if the wheels will fall off.

Based on what I believe you want to do, yes, the wheels will come off. There is nothing to hold the axles into the bearing.

Please be careful if you try something like this. I can't see how it could be safe.

I have a huge problem with my differential. My truck jerked to a complete halt one day-luckily at low speed. I took off the differential cover to reveal many of the teeth on the ring gear had been sheared completely off. The fluid was ruined completely and probably all the bearings-I plan to replace everything. The Question is: it is a 4 door, originally a 4 by 4 (the transfer case does not work) and I want to know what size/type is my differential as the ID tag was not there on the differential. Is there a way to tell from the VIN number? There are many ID numbers in the glove box but that is almost worn away and unreadable. What can I do with only the most basic tools to measure and get a new differential as there are several different differential sizes when I call about parts. Also the pinion shaft bolt has welded to one of the internal gears and I cannot get the pinion shaft bolt out. I spent a full day hammering on it and it only budges a few millimeters. I have given up and will bring it to a differential shop-however they have all told me I need to obtain the replacement differential and I don't know which one it is. Help would be greatly appreciated.

Axle ID stamped on front of axle housing tube need to wire brush. Fist 3 digts are axle ratio next is axle assembly build last 3 are date manufactured.
Could be 7 5/8 or 8 5/8 ring gear

Thank you for the help. All the part places are asking me if the ring gear is 7 5/8 or 8 5/8. How do I check which one it is? It is a 5 bolt axle, with an open differential, and the VIN number for the vehicle is:
1GNDT13W9V2196408 If that helps? It would really help if I can find out what size it is or how to measure it with basic tools?
Thank you very much,
Ryan


[quote:3b2430d4be="Docfixit"]Hi
Axle ID stamped on front of axle housing tube need to wire brush. Fist 3 digts are axle ratio next is axle assembly build last 3 are date manufactured.
Could be 7 5/8 or 8 5/8 ring gear
Hope this helps
Thanks for donate[/quote:3b2430d4be]

Thank you. So how do I determine if it is 7 5/8 or 8 5/8? Is that in the number on the axle housing tubing?

Yes on housing first 3 digits are axle ratio. you could measure ring gear to get size

i keep going through axle bearings,i put a new one in about two blocks and thump thump it goes

you may need another axle. those axles were well known for being soft and were hard on bearings. when you remove the axle, carefully check the bearing mating surface for roughness or a gray like area. it wouldn't look polished like the rest. if it is replace it. Also before reinstalling the axle, lube the bearing with grease or oil.

i need to know the gear ratios on my truck so i can replace the rear end

the rear axle ID is stamped on the forward side of right axle tube. the first 3 digits will indicate the rear axle ratio, the next digit indicates the axle assembly build source code, the next 3 digits indicate the day built in Julian Date form and the last digit identifies the shift build (first or second).

I believe i've lost my rear end. My truck makes a clunking noise and every 100' or so it locks up solid. If i reverse it frees itself again and i can proceed for about another 100'. I think theres a piece popping around in there and from time to time its catching and locking the other parts. If you can confirm this or suggest something else it would be appreciated. In the mean time, if i do need a new rear end is it possible that there are multiple different sizes or are the ratios across the board. (I have another one scrapped) Thanks for your help.

J Kennedy

Hi there, you may have a broken tooth on the crown wheel or pinion, also the spider gears may be damaged, you will have to remove the diff centre to inspect, the ratio will be etched into the crown wheel and pinion set, you would be best advised to get the same ratio.

Mark (mhpautos)

I've a fullsized blazer, with 3.73 gearing, and I'm wanting to change this to a 3.08. Is this alright? I don't tow anything,,,,I shall, but nothing huge, and I won't do any SERIOUS 4wheeling? Is this an alright change? I'm thinking of gas mileage,,,and reducing my tire size, from 31/10.5's to about a 235/75/15....... Please tell me,,,what do you think? Give me some answers , PLEASE! Mg

Whatever gear ratio you use in the rear, you have to adjust the front accordingly. They have to be within a certain percentage of each other or the transfer cse will be ruined.Find a local shop that does this and see what they suggest, or just go to the smaller tire. Depending on how you drive though, you may not get better mileage. The more RPM's an engine turns the more fuel it uses. Stock size tires would probably yield the best mileage

Yes,,,I understand,,that :"whatever" I change to, I 'll have to change the front, accordingly, however, my desire, is that "IF" I go from a 3.73, to a ,,,,,,for example a 3.08,,,,,it'll give me the better mileage,,,,,,(with smaller tires)> yes,,,,but is it/will it,,,,? > Still be able to do the "normal" 4wd tasks,,,,,just not "as much" towing ability,,,,,,,,,,would that be alright? Sincerely, Marcel / gaud29@aol.com

some 4wd performance will suffer. More gear is better , depending on what you are doing, but if it is just basic 4wd for snow aound town you will be ok

I have a 1988, K5 Blazer, automatic transmission, 4 wheel drive with a 5.7L engine with about 100,000 miles on it. I lost the oil in the rear end and locked up or seized the bearings where the yolk enters the rear end. Possible damage to axle bearings also. I am trying to decide rather to fix what I have, if possible, or find a whole rear end at a salvage yard. I need to know what size rear end came in this vehicle. I have opened it up and all the gears are in pretty good shape. I am fairly sure, no positive, that it is the stock rear end for that year. Can you please tell me what size rear end I have in it? Do you think it is worth re-building? My axles turn freely with no growling or noticeable damage. I would replace anyway. I believe my main problem is the bearing where the drive line and yolk enter the rear end. That is froze up solid, or pretty close to solid. I will included a pic I took and maybe that will help determine some of this. Thank you very much in advance. DonH Sterling, CO

:?: :?:

That is called a 10 bolt rear end. Count the teeth on the ring gear and then divide the number of teeth on the small pinion gear that will give you your ratio. Make sure you measure the overall width and check the spring perches.

If the pinion bearing seized and there is a lot of metallic flaking in the case you are better getting a used rear end and installing it.

Please let us know if you need anything else to get the problem fixed.

Cheers

I am installing new gears I the front end of my vehicle and I got the old shim on the new pinion and new bearings. When I tighten the nut the pinion is too tight to turn and it's not over tightened I barely wrenched it on.and if I back off a bit and turn the pinion then I can hear the (new) crush sleeve has not been crushed it's moving in there. I'm thinking maybe have to go with smaller or no shim on pinion?

Welcome to 2CarPros.

I need to know which differential you have. There are several that could have been used. Here is the list of possible differentials.

Adjustments
Borg Warner
Dana/Spicer
Timken/Rockwell - 12 Inch Ring Gear

Let me know.

Joe

It's a GM 10 bolt 8.5 ring gear.

Welcome back:

I believe this is what you need. Take a look through it and let me know. The attached pictures correlate with the directions.

__________________________________________


Adjustment
1. Install pinion bearing races in housing using a suitable driver.
2. Lubricate pinion bearings and install bearings in races.
3. Mount depth gauging jig in housing, Fig. 8, noting the following:
a. Assemble gauge plate onto preload stud.
b. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug.
c. Rotate tool to ensure bearings are properly seated.
d. Hold preload stud and tighten nut until 20 inch lbs. of torque, which is required to rotate stud. To prevent damage to bearing, tighten nut in small increments, checking rotating torque after each adjustment.
e. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing.
f. Mount arbor and plunger assembly in housing, ensuring side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving, Fig. 9.
4. Mount dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger.
5. Preload indicator 3/4 revolution and secure to arbor mounting stud in this position.
6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size.
7. Slowly rock plunger rod back and forth across button while observing dial indicator.
8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting.
9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a ``nominal'' pinion.
10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9.
11. Select pinion depth adjusting shim as follows:
a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9.
b. If pinion is stamped with a minus ( - ) number, subtract that many thousandths from dimension obtained in step 9.
c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness.
12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings.

Installation
1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers.
2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing.
3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with a drift while assistant holds pinion in place. Old pinion nut and a large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used.
4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke.
5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut.
6. Hold driveshaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero.
7. When endplay is reduced to zero, check pinion bearing preload using a torque wrench.
8. Continue tightening pinion nut in small increments until 35-40 inch lbs. of bearing preload is obtained with new bearings or 20-25 inch lbs. of bearing preload is obtained with used bearings, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload.

Take care,
Joe