Builds - Summer time Black FJ40 re-baselining (1 Viewer)

[DangerNoodle]

Is your pinion nut loose? It may cause that.

 

[TexFJ]

I'm thinking that the gears may be worn or there is a preload that needs to be reset. Guess I would have to open it up and take a look. I'm guessing 35-40 degrees is a little too much.

 

[TexFJ]

As in the backlash?

Yes, thanks for making sure I clarify. I'm assuming it's much more backlash than there should be.

 

[DangerNoodle]

Yes, thanks for making sure I clarify. I'm assuming it's much more backlash than there should be.

I'd check the pinion nut to see if it backed off. Changing that bearing preload can do that. Don't overtighten the crush sleeve, though.

 

[TexFJ]

Transmission is back in... finally, the lift really came in handy besides getting roof racks off.

 

[TexFJ]

Here's the difference in the backlash between front and back.




took the flange off, no guard on the front as there is int he back

Pinion gear play seems not right... bad bearing?

pinion gear play... not normal

youtu.be

 

[TexFJ]

Anybody know the correct path for the speedometer and parking brake cables? The pic makes overstates the proximity to exhaust pipe, but further is better. Wondering what Toyoda did.

 

[TexFJ]

I'd check the pinion nut to see if it backed off. Changing that bearing preload can do that. Don't overtighten the crush sleeve, though.

Couple of questions here to get better understanding:

- if a nut backed off, would that changer the backlash? I believe that would move the pinion gear closer to the ring gear hence reducing the backlash.
- I can't find a crush sleeve in this differential. I thought maybe that it was left off but I can't find it in the parts catalog for the '73 F40.
- when i removed the nut and opened things up, the outer bearing came right off. is it supposed to be lose or pressed on?

 

[DangerNoodle]

Couple of questions here to get better understanding:

- if a nut backed off, would that changer the backlash? I believe that would move the pinion gear closer to the ring gear hence reducing the backlash.
- I can't find a crush sleeve in this differential. I thought maybe that it was left off but I can't find it in the parts catalog for the '73 F40.
- when i removed the nut and opened things up, the outer bearing came right off. is it supposed to be lose or pressed on?

If the nut backed off, it changes the pinion bearing preload, which can cause that.

I'm not sure if these have crush sleeves behind the nut, but I think they do. I'm sure someone more knowledgeable than me can add to that.

The outer bearing is loose, which is why the nut needs to be at the correct tightness to keep the pinion gear in place.

 

[pb4ugo]

The outer pinion bearing does slide off the pinion shaft. Earlier stk 3rds shouldn't have a crush sleeve. Once the bearing is removed, you should find some thin adjustment shims and a small spacer. A crush sleeve would be in this location if it has one and it would not have shims. These shims and washer rest on the shoulder of the pinion shaft. The shims or crush sleeve go between the inner and outer pinion bearings. The shims and spacer are used to adjust the preload. Pinion depth is determined by the shims between the inner pinion bearing race and the 3rd member housing.

 

[TexFJ]

All makes sense, except it seems like I won't be able to reduce the backlash, IMO. When I tighten the nut to adjust the preload, it actually pulls the pinion away from the ring gear and probably causes more backlash. Perhaps there's another reason for it. I'll reset the preload and hopefully it proves me wrong.

I'm thinking that those the shims and spacers in there? Or perhaps they're gone.

 

[pb4ugo]

In post #86 with the 2 videos showing how much the pinion flange rotates. The rotation is not all backlash between the ring and pinion. Most of the rotational slop is from the spider gears coming in contact with either the carrier or the side gears. Only a very small amount of rotation is from the backlash setting between the ring and pinion, unless all the bearings are shot. The carrier is the part the ring gear bolts to. If you want to see this you can remove the rear cover and watch what happens when you turn the pinion flange and look at the spiders. Backlash is measured between the ring and the pinion, and the 3rd member has to be removed from the housing to adjust it. If all the bearings are good the Backlash settings are usually less than .020" Preload refers to rotational resistance between the pinion bearings and races, and has nothing to do with the actual ring and pinion setup. Its a measure of resistance to insure the bearing are seated correctly. You'll find the preload spec on new bearings to be higher than on old bearings. After driving it for a while, the preload will slightly go away as the bearings and races seat.

B4 you removed the pinion nut and yoke/flange, did the flange have any movement in and out or side to side(wobble)? If not then I'd bolt it all back together. And torque the pinion nut to spec. In your last video you can see the shims and pinion spacer 1 sec in. close up. There's a very slight shoulder just below them. The ring and pinion are helical gears and they don't mesh like straight cut gears. When you tighten the pinion it is supposed to move away from the pinion. The gears mesh at a sweet spot and create a contact pattern. If you look in your manual on diff setup you will find a page with pics of contact patterns and adjustments to get the correct contact pattern.

 

[TexFJ]

In post #86 with the 2 videos showing how much the pinion flange rotates. The rotation is not all backlash between the ring and pinion. Most of the rotational slop is from the spider gears coming in contact with either the carrier or the side gears. Only a very small amount of rotation is from the backlash setting between the ring and pinion, unless all the bearings are shot. The carrier is the part the ring gear bolts to. If you want to see this you can remove the rear cover and watch what happens when you turn the pinion flange and look at the spiders. Backlash is measured between the ring and the pinion, and the 3rd member has to be removed from the housing to adjust it. If all the bearings are good the Backlash settings are usually less than .020" Preload refers to rotational resistance between the pinion bearings and races, and has nothing to do with the actual ring and pinion setup. Its a measure of resistance to insure the bearing are seated correctly. You'll find the preload spec on new bearings to be higher than on old bearings. After driving it for a while, the preload will slightly go away as the bearings and races seat.

B4 you removed the pinion nut and yoke/flange, did the flange have any movement in and out or side to side(wobble)? If not then I'd bolt it all back together. And torque the pinion nut to spec. In your last video you can see the shims and pinion spacer 1 sec in. close up. There's a very slight shoulder just below them. The ring and pinion are helical gears and they don't mesh like straight cut gears. When you tighten the pinion it is supposed to move away from the pinion. The gears mesh at a sweet spot and create a contact pattern. If you look in your manual on diff setup you will find a page with pics of contact patterns and adjustments to get the correct contact pattern.

Wow, great post. Unfortunately I don't have a back panel on the front diff that i can remove like on the rear diff so I would have to take it out. I don't remember any side to side nor in/out movement so perhaps I'll try to torque the pin for now. If it doesn't fix things then i'll take the 3rd member off to inspect spider gears.

I just think that the backlash that you see in the videos while turning the front diff vs. the rear is out of spec. Nice little mystery.

 

[pb4ugo]

Removing the frt 3rd requires a lot of work to remove the axles so the 3rd could be removed. I only mention looking at the rear because its easier to do and will help explain why there's so much rotation in the pinion flange. From what I see, I would install a new seal and put it back together.

 

[TexFJ]

I tried to get the cover off last week and it's cooked on there. Yup. gonna close it up and set the preload. Maybe when I rebuild the axle, i can tackle getting it perfect.

 

[TexFJ]

waiting for parts, so I'm doing some superficial improvements.

Put the wrong bulb in....

going back to the OEM Cygnus color.

 

[TexFJ]

You may notice, there is no windshield fastening hardware on the hood. PO removed it AND grinded off the lip that held the hook when the windshield was up. I want to experience the wind in my hair so I need to decide whether to recreate the lip or make some holes for the later model fastening h/w.

 

[merbesfield]

Yours will help me understand what mine was supposed to look like.

Was there any options that that could have bolted on the front in this hole? PO filled a lot of holes in the body (emblem holes, rubber windshield pads, etc.) but not this one.

View attachment 2794538

Strange, but my 82 has a hole just like that.

 

[TexFJ]

Bought a used OEM center console, seems like people prefer the tuffy boxes. Refinished but wondering if there are any 3D printed cup holders for these?

 

[JohnnyFish]

Yes, I bought one earlier this year. I'll try to figure out where it came from.

1979-1980 FJ40 Double Cup Holder - Etsy

This Vessels item by BH3DPrinting has 28 favorites from Etsy shoppers. Ships from Whitley City, KY. Listed on Mar 21, 2024

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