pauls340
Well-Known Member
Is there a way to fix this Yoke seal leak without taking the pig out?
Yoke seal leak on 741 posi fixable?
- Thread starter pauls340
- Start date
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Just remove the nut on the yoke, remove the yoke and replace the seal. If the sealing surface on the yoke is grooved, you can install a Redi sleeve and make it good as new. The National part number for the sleeve is 99187. They cost $25.00. The seal part number is 8515N or 5126 National.
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Alaskan_TA
Well-Known Member
Absolutely.
Been there done that, even wrote a short article about it that be read at The 1970 Hamtramck Registry - Nostalgia and Old Cars
It can be done with 741 & 742 cases, so they have an advantage over the 489s with the crush sleeve in this regard.
Been there done that, even wrote a short article about it that be read at The 1970 Hamtramck Registry - Nostalgia and Old Cars
It can be done with 741 & 742 cases, so they have an advantage over the 489s with the crush sleeve in this regard.
Bulldozer
free ice cream sandwiches
wtf is a posi
pauls340
Well-Known Member
That's what happens when you get a brain-fart in 1973 and you sell your original 1971 Demon340 and you go from a Sure-Grip to a posi....but i'm backnow and going on 25 years.
Just be sure to re-torque the nut to 250ftlb,
fishy68
Tyr Fryr's Inc.
If you do that you might strip the threads. The posting (even in some service manuals) that say a 741 pinion nut should be torqued to 250 ft. lbs is incorrect. It's only a 5/8" thread so it only needs 150 ft. lbs. The newer 489 housing with the larger nut (and consequently larger threads) is the only one that needs 250 ft lbs torque. I also use loctite on them just to make sure they stay in place
john-9
Well-Known Member
741/742/489 pinion coarse 10 spline nut is 3/4-16 thread -- fine 29 spline nut is 7/8-14 thread --- not 5/8 thread.
Well you boys do what works for you but what has worked for me for over 40 years is following the advice of the Chylser factory service manuals. It states 240 ft lbs for the 741 pinon. Sorry not 250.
Calls for 240 ft lbs to set the preload so don't think the threads are going to strip.
fishy68
Tyr Fryr's Inc.
The preload is set by shims on a 741, not torque like on a 489. And I've seen them strip when torqued too much
fishy68
Tyr Fryr's Inc.
I believe you are correct on the thread size of the smaller thread. I know it was smaller and was going off memory and just had surgery and taking pain meds so my memory is clouded. How many large thread 29 spline 741's have you seen? I haven't seen any. Not positive but I always assumed that in 40 yrs. of working on them and not seeing any 29 spline 741's they didn't make them, but maybe it was just luck of the draw.
So why does the factory service manual say to set the preload by torquing to 240 ftlb? The shims set the pinon depth. The factory manual as in by the people that designed this. Your saying that the they are wrong? Sorry I'll believe them over you, nothing personal. I've torqued them to 240 for 40 years and never come close to stripping one.
mopowers
Well-Known Member
I always thought preload was set on 741s and 742's by shims, not by torque.
How do shins set a load? Shims adjust a depth. Torque sets a load.
mopowers
Well-Known Member
How long you been doing this?? Pinion depth and pinion bearing preload are set by shims on both 741 and 742 diffs, whereas 489s use a crush sleeve to set pinion bearing preload.
Decades. Yes I know the difference between the cases. Have several on the shelf.
So how do you set the preload on wheel bearings???? Do you shim wheel bearings???
So how do you set the preload on wheel bearings???? Do you shim wheel bearings???
All I did was give advise from the FSM. Didn't make anything up or have my own calculations. The book says to adjust the depth with the shims and set the preload with torque and torque to 240 ftlbs. Some on here says the book is wrong. Sorry I'm going with the book.
pishta
I know I'm right....
shims set preload..."...tighten the (pinion) nut to 240 foot- pounds torque. Turn the tool several revolutions to permit the bearing rollers to seat. After the bearing rollers have been properly seated measure the bearing preload by rotating the tool with an inch-pound torque wrench. With the bearing lubricated with Mul- tipurpose Gear Lubricant, the correct preload specifi- cations are from 45 to 50 inch-pounds torque. If the bearing adjustment does not conform to specifications it will be necessary to change the adjustment by either a thicker or thinner pinion bearing spacer. If the preload is too great it will be necessary to install a thicker spacer and if the preload is not sufficient a thinner spacer will be necessary.." regarding pinion with bearing spacer rear end (741/742) from 1965 FSM
You can't set the preload with torque if they give you a torque setting to use (240 ft/lbs)...? That has to be set with a variable shim pack at 240 ft/lbs pinion nut torque. That's how I read it.
You can't set the preload with torque if they give you a torque setting to use (240 ft/lbs)...? That has to be set with a variable shim pack at 240 ft/lbs pinion nut torque. That's how I read it.
Yes I guess you are correct about the shims but you still torque to 240 foot-pounds, not 150. The last few cases I've done were 489 cases. Been about 6 years for a 741/2 case and just did bearings and didn't have to change shims to get in specs.
Yes I'm thinking the shim thing backwards. I'm trying to think if I've ever had to change the shims on a 741/2 case. Don't think I have. I've never changed out the carrier just the bearings and the original shims always worked out for me.
Still holding firm on the 240 ftlbs thingy though.
Still holding firm on the 240 ftlbs thingy though.
The large shim between the pinion and the large bearing sets the pinion depth. The smaller shim pack on the opposite end between the pinion and smaller bearing is how preload is set.
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