Thrust block removal

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ChrisN68

ChrisN68

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I have read a few threads on this topic, but can't seem to get a clear answer from existing threads, so I figured I'd just ask. I have a peg-leg 741 differential with axles that have been changed over to green bearings. Upon installation, I found that the axles wouldn't seat, and so researching it has led to realizing that I need to remove the thrust block. How do I remove the thrust block on a non-SG unit (all the posts I found are for SG units only)? Do I need to take the diff apart again to get to it? I don't see a pin, so I don't think I'll get away easy, but hoping someone with experience can coach me through it. Advice or pics would be greatly appreciated!
 
Your in a different situation. With the open diff. you have two choices.
1) shorten the axles( only takes a little)
3) Remove the third member,drive the small roll pin out that holds the spider gears, slide the pin out enough to remove the float alxe butt spacer.
 
I fabricated a couple of spacers to install between the backing plates and the mounting flanges. This was for a different application,but I don't see why it wouldn't work for you.
 
Thank you both for your replies. I am adding disc brakes, and I'm already maxed out on the spacers, so the option from AJ won't work for me. Before I resort to shortening the axles, can the roll pin be removed without taking the carrier out of the third member? I'm trying to avoid having to redo the entire setup procedure, if possible.
 
ChrisN68 said:
I have read a few threads on this topic, but can't seem to get a clear answer from existing threads, so I figured I'd just ask. I have a peg-leg 741 differential with axles that have been changed over to green bearings. Upon installation, I found that the axles wouldn't seat, and so researching it has led to realizing that I need to remove the thrust block. How do I remove the thrust block on a non-SG unit (all the posts I found are for SG units only)? Do I need to take the diff apart again to get to it? I don't see a pin, so I don't think I'll get away easy, but hoping someone with experience can coach me through it. Advice or pics would be greatly appreciated!
Click to expand...

open diffs use a solid thrust block same type as the suregrip units (spring/cone type) -- you have to remove the spider gear cross shaft to remove it , shorten your axles a bit ,, it is the best and easiest option.
 
If I go that route, what is the best way to shorten the axles? Can it be done at home, or do I need to take it to a machine shop?
 
ChrisN68 said:
If I go that route, what is the best way to shorten the axles? Can it be done at home, or do I need to take it to a machine shop?
Click to expand...
You can cut them with an abrasive wheel, but it'll be slow going. Then grind a chamfer back on the cut edge. Have to deburr each spline too, or they will never go back into the splines. There is nothing overly fussy about this, all you're doing is creating clearance.
 
Thanks again for the replies. I'd like to remove the thrust block as my first option, will consider the axle shortening if need be. I appreciate the advice. Does the carrier need to be removed to get at the block, or can it be done with the carrier in place? I couldn't find anything in the service manual, or online, to serve as a clear guide to even getting at the spider gears, and I'd like to do it right...
 
I never tried it with the carrier in the case. Even if you can I think it would be difficult. Removing the carrier isn't that hard. Check the backlash before you remove it and reinstall it with the same amount. Should be .006-.010.
 
If we're still taking 8.75s here; the pumpkin needs to be out,the carrier removed and the case split to access the little pin. It is held captive by the case halves.
Then yeah, you only have two options left and removing the block is probably the wisest, cuz it's reversible.
 
AJ/FormS said:
If we're still taking 8.75s here; the pumpkin needs to be out,the carrier removed and the case split to access the little pin. It is held captive by the case halves.
Then yeah, you only have two options left and removing the block is probably the wisest, cuz it's reversible.
Click to expand...
He is talking about an open carrier. The case doesn't split like a SG.
 
Thanks for all the help with this one. The thrust block is out, here's some info on what needed to be done, in case anyone else has the same question in the future:
-Carrier must be removed from case.
-Ring gear must be removed from carrier, as it blocks the shaft from being removed (remember, bolts are L-hand threaded)
-Pin needs to be driven out with a long punch (I found this video useful, even though it shows a dana rear - same process: )
-Shaft can then be tapped out just enough for thrust block to be removed
-Remove thrust block sideways, through the axle shaft tunnel
-Reverse the process to reassemble
 
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