1991 Previa Van Rear Differential going bad

Most differentials are set up like this. There is a steel bar that is i the middle of the gears, this is held in with a bolt. remove the bolt. pull the bar out. Then push the axles in the center. There is a c clip to remove from the axle. They will come out easily. Pull the axles out. Once the axles are out the hog head as they call it, will come out. Just watch as the inner gears will come out also. And will have to be placed in the same spot. Kinda of push in and see. let me know

Depends on what parts are needed. They range from $20.00 to several hundred. First find out where the noise is. Start at the drive shaft, check the universal joints.Check wheel bearings/ seals for leaks. Take off the rear cover and look at the differential. check for missing teeth. missing clips , metal on the bottom. Let me know I can help.
Randy

Low gear oil wont affect engine performance, unless excessive heat has warped something in your differential and its binding. Is the vehicle hard to accelerate as well as it brakes quickly once you stop accelerating. If not, you likely have a different problem. What led you to gear oil, is there noise in your differential. Gear oil is just what it says Oil for the gears. when it runs low they can overheat, but they should get noisy if the oil is low enough not to lubricate and the telltale heavy oil should be all over underneath your engine and transmission in front wheel drive and all over your differential in rear wheel drive

Standard Differential, Rear 8.8 and 9.75 RG......GL-5
All TEMPS......75W-140 [3]
SEVERE GEAR 75W-140 Synthetic EP Lubricant (SVOQT)
80W-140 Synthetic Long Life Gear Lube (FGO05)
Limited Slip Differential, Rear 8.8 and 9.75 RG......GL-5*
All TEMPS......75W-140 [4] [3]
SEVERE GEAR 75W-140 Synthetic EP Lubricant (SVOQT)
80W-140 Synthetic Long Life Gear Lube (FGO05)
Differential, Front 8.8 RG......GL-5
All TEMPS......80W-90
SAE 80W-90 Synthetic Gear Lube (AGLQT)
SEVERE GEAR 75W-90 Synthetic EP Lubricant (SVGQT)
75W-90 Synthetic Long Life Gear Lube (FGRQT)
SEVERE GEAR 75W-110 Synthetic EP Lubricant (SVTQT)
Transfer Case,......MA
Synthetic Multi-Vehicle Automatic Transmission Fluid (ATFQT)
Torque-Drive Synthetic Transmission Fluid (ATD1G)
Fluids
Power Steering Fluid......MA
Synthetic Multi-Vehicle Automatic Transmission Fluid (ATFQT)
Power Steering Fluid......MA
Torque-Drive Synthetic Transmission Fluid (ATD1G)
Brake Fluid......HB
AMSOIL Brake Fluid DOT-3 (BF3SN)
Clutch Fluid......HB
AMSOIL Brake Fluid DOT-3 (BF3SN)

I'd say yes. The differential fluid is often overlooked by oil change technicians, even though it's something that should be topped off periodically.

It probably would cost more than that to repair it once it wears out.
Axle Housing Assembly Removal & Installation To Remove:

1. Lift the vehicle.
2. Drain the lubricant from the rear axle housing.
3. Remove the rear axle assembly from the vehicle.
4. Remove the brake caliper brackets from the rear hubs.
5. Remove the rear cover and gasket from the rear axle housing.
6. Remove the rear axle shafts from the vehicle.
7. Remove the rear differential assembly from the vehicle.
8. Remove the brake backing plates from the rear hubs.
9. Remove the rear drive pinion shaft yoke and seal from the drive pinion.
10. Remove the drive pinion from the rear axle housing.

To Install:

1. Install the drive pinion into the rear axle housing.
2. Install the rear drive pinion shaft yoke and seal onto the drive pinion.
3. Install the rear differential assembly into the vehicle.
4. Adjust the differential side bearing preload and the backlash.
5. Perform a gear tooth contact pattern check.
6. Install the brake backing plates onto the rear hubs.
7. Install the rear axle shafts into the vehicle.
8. Install the rear cover and gasket onto the rear axle housing.
9. Install the brake caliper brackets onto the rear hubs.
10. Install the rear axle assembly into the vehicle.
11. Refill the lubricant in the rear axle housing.
12. Lower the vehicle.

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I think that changing the fluid would take about an hour, and depending on the garage, and the labor rate, that they might elect to take the rear cover off of the differential, and drain it that way and replace the fluid once it was put back on. He could inspect the gears while the cover was off and tell you how bad it was.'

Do you hear any clunking or gear mesh noises from the rear when putting it in gear or running the vehicle?


Some mechanics would simply top off the fluid and wait until it wears out, which could be several thousand miles in the future.

Use gear oil for it of the recommended viscosity in the service manual.

Generally thicker than motor oil.

So, adding fluid would cost only the amount of the fluid plus some labor.
A bottle of fluid might cost $9.99 or so depending on where you get it.

You might be able to do this yourself if you crawl under there, remove the fill plug at the top, and just add gear oil. If there isn't enough room you might drive it up on some ramps and then crawl under there.

Hi, there, Check your break pads. Could be from there.
cheers

The rear diff. turns the rear wheels. It is located in the middle of the rear axle. It won't last long if you ignore it. May just need dearing's but if it is driven the cog wheels will grind to dust or drop off this can cause the rear axle to seize up and can be a danger because the back wheels will lock up. If you are going to fix it yourself let me know and I will be able to guide you through the process

juddering is UK english for shuddering in US english. The center bearing shouldn't move, i/e/ the shaft should rotate w/o side play in the bearing, but the rubber mounts for the bearing should be flexible. The needle bearings in the universal joints in the front to rear drive shaft can go bad, causing noise when accelerating and they're not changeable w/o special tools. Your problem also sounds like differential, which would mean that you need to change the gear oil in the rear differential. As the oil ages it stops working properly in the limited slip differential even if visually OK. Do the front differential at the same time, engine heat ages it even faster. The center diff is in the AT, so you would change the AT filter and fluid.
How to tell which problem you have... in a parking lot with dry pavement, stop the vehicle, turn the wheel hard right, accelerate a moment, and repeat hard left and centered. If its worse turning, than straight suspect the differential fluids first. If its the same turning or not and especially if its the same on wet or dry pavement and at slow and high speed then look into the propeller shaft first.

there is a fill plug on the side of the carrier housing on the nose of it, but if the rear end is noisy it is to late, u have damaged the gears or the bearings or both.

Is isnt the rear end it would be very bad shaking and wouldnt last long because it would throw a bearing out. So its most likly the wheel bearing and you can just take it to a local automotive shop.