Third Member Swap - DENIED!!! (1 Viewer)

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PabloCruise

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Dammit!!! :mad: :mad: :mad:

So I was getting ready to swap out my rear third member w/ a front third I got from a 1969 40...

I was doing some reading in the FSM before hand and came up with these conclusions regarding pre-load: (originally posted here)

The FSM has you set up the drive pinion and measure pinion preload. I believe at this point the ring gear and carrier are not present in the third member.

The FSM states:
Specified Preload (starting)
New Bearing 16.5-22.6 in-lb
Reused Bearing 7.8-11.3 in-lb

Then you keep going, put the ring gear on the carrier and install that. Then set your side bearing preload. Then you measure the overall preload.

I just got the issue that was hanging me up...

The FSM states:
Specified Preload (starting)
(For both new and reused bearing) 3.5-5.2 in-lb + DRIVE PINION PRELOAD.

I kept missing the + DRIVE PINION PRELOAD part and wondering how the hell the overall preload part could be less than the drive pinion preload.

It sounds like you can evaluate a third member with ring gear carrier installed by giving the pinion a spin and the acceptable range of starting preload could be as low as 11.3 in-lbs OR as high as 27.8 in-lbs?

I tried my replacement third with a inch-lbs torque wrench - got about 5 in-lbs...

I tore into it and this is what I saw...
895F.JPG
 
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are you just swapping the r&p? or the whole third member? for whole third member, i just readjust the backlash to something that doesn't resemble half worn out and bolt in. shouldn't have to do preload unless your doing r &p or replacing bearings.
 
It looks like an extreme example of a "spun" shim pack. The two shims in the picture are the thin type. They are all the same thickness (0.25 mm or .0098 inch) and there can be 0-4 total. The preload is set by the thicker "preload washer" which come in 9 different sizes from 2.75 - 3.0 mm. Start by replacing the thin washers and then check the preload. If it is too tight, you will need a thicker preload washer. If it is too low, you can sand down the washer you have to get it in the right range. The FSM has all the part numbers for the shims and washers.
 
Check out Charlie Glabe's excellent R&P set up article in the Tech section.....an absolute MUST READ for anybody doing their own differential/gear work. His article is very informative.....Cheers!
 
1Fine40 said:
Check out Charlie Glabe's excellent R&P set up article in the Tech section.....an absolute MUST READ for anybody doing their own differential/gear work. His article is very informative.....Cheers!



AKA Pin_Head
 
PabloCruise said:
Pin Head, do you mean replace the 2 thin shims?

Sounds like a good place to start.

Thanks!

Yes, replace the thin shims and try it. The shims go first and then the washer then the flange.
 
Pin_Head said:
Yes, replace the thin shims and try it. The shims go first and then the washer then the flange.

I want to make sure I get this right the first time...

The FSM manual illustration makes it look like it goes washer first, then shims, then bearing, slinger, then flange?
pinion-shim-resize.jpg
 
Pin_Head said:
The FSM is amost always correct.

"almost always"?

So I take it you are verifying your previous statement:

Pin_Head said:
Yes, replace the thin shims and try it. The shims go first and then the washer then the flange.

Thanks,
 
No, I would go by what the FSM shows. I don't remember, but I did use the FSM. There are only a couple of errors in the manual and most are just typos
 
monday a.m. just saw your post

:frown:
man that blows, were you able to finish it up?
or did toyota have to order your shim?

sorry for the bunk third TJ.

jim
 
2badfjs said:
:frown:
man that blows, were you able to finish it up?
or did toyota have to order your shim?

sorry for the bunk third TJ.

jim

Dude - not at all, I think it is more common than I thought.

Could not finish - I'll get shims, don't want to fuq this one up. I am learning all kinds of cool things about pinion preload!!! Randy's Ring and Pinion has some cool tech articles.

The thing feels great when you turn it by hand.
Everything looks great too! Hot tank cleaned everything up nicely.

I had to go in there anyway to swap flanges and thought I better check after my last fiasco when I did not investigate.

Getting shims in this week - should have them in time to get after it this weekend!
 
Evaluating third members

PabloCruise said:
It sounds like you can evaluate a third member with ring gear carrier installed by giving the pinion a spin and the acceptable range of starting preload could be as low as 11.3 in-lbs OR as high as 27.8 in-lbs?

Theo refined my logic a little bit in the other post - copying here for future searchers...

theo said:
Almost right.
If you reuse your pinion bearings then the range is 11.3-16.5.
If you replace the pinion bearings the range is 19-27.8.
 
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get it done

and come do holy cross in july...
it'll be my first time on holy cross ;)
 

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