3.23's work well with a 3.09 low gear four speed, not so much with a 2.66 low gear. Not with a small block, anyway. Just my opinion based on my own experience.
getting an 8 3/4 from a 69 dart
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What would my 69 833 have
Or do I need to open it up
Or do I need to open it up
it likely has the 2.66 1st. but trust nothing and verify everything, these cars are 50+ years old
also, i wouldn't worry the slightest about a 2.66 1st. it's deeper than a 904 (2.45) or 727 (2.54)
it'll be fine with 3.23's as long as you don't have like 28" tall rear tires.
Tires are 245/ 60 r15 not too tall
Going to go threw the trans anyway
But the automatics have a torque converter to multiply torque; 4-speed does not.
My 65 Barracuda was fast off the line with a 3.09 low gear and 3.23 gears; it was a dog off the line with 2.66 low gear. Then I figured out I could run my original gearset in a 69 trans. End of problem.
Building my 340 for more torque then hp...
different strokes for different folks i guess.
Some fast is fast .....enough
john-9
Well-Known Member
clutch style sure grips for the 8-3/4 diff have NO springs as shown in your pictures ,, look at the cheap 8-3/4 clutch type units on e-bay to compare yours to ,, post a pic of the center pin in your sure grip case ,,want to see if the pin has oblonged the hole in your case which means its scrap, there are NO replacement parts available for the cone type so if your case ,, side gears or spider gears are shot you have to locate another unit to salvage parts from.
So cone type is the better one
Should I re-gear this one if it's good
Don't really want too tight of a posi
Should I re-gear this one if it's good
Don't really want too tight of a posi
340sFastback
Well-Known Member
Its an original cone type sure grip. Once they get a lot of miles on them the cones bottom out in the housing and excessive spider gear clearances leading to center pin shearing. Thats what happened to my original cone. If anyone has a cone type best to change gear oil frequently because its a metal to metal with metal tint in gear oil.
Doctor Diff sells new clutch sure grips for 8 3/4s
Doctor Diff sells new clutch sure grips for 8 3/4s
I have this 3.23 ring and pinion available for a 489 case.
[FOR SALE] - Dodge Chrysler Plymouth Mopar 8.75 8 3/4 3.23 Gears Cheap Look!
[FOR SALE] - Dodge Chrysler Plymouth Mopar 8.75 8 3/4 3.23 Gears Cheap Look!
Here is a 1969 8 3/4 out of a '69 GTS, vent on top of driver's side housing.
☆☆☆☆☆
☆☆☆☆☆
No,,,the cone type is Not the better one.
The clutch type made by Dana,,,,are the Sure grip units .
The cone type made by Borg Warner are the limited slip units .
They worked well but wear out in the street after about 50,00 miles or so back in the day .
They just wear to the point that the cones can’t grip the side of the unit .
They can be reworked and made to function properly again,,,it just requires some machine work and shimming the springs to compensate for the pressure.
Tommy
Ok then I'm just going to sell it as a unit
heres pics of the pin not easy to see
looks tight ,its been apart gear oil has a glitter back lash is a little too tight for me ,didn't put a dail on it
so is this a better diff or should i look for a clutch type ...
@junkyardhero
The A904's and A727 have the same 1st gears. it's 2.45:1.
I could be wrong, the only other 3 speed Torqueflite's to have different 1st gear ratios are the A999 & A998's at 2.74:1 (which are basically suped up A904's).
john-9
Well-Known Member
in the 2nd pic looks like the center pin bore is oversized which means your pin has spun in the bore or the pin has a super large chamfer on the end which i doubt , so you probably have a junk unit ,, do your self a favor and buy a new clutch style unit . parts are available for these and they work very well .i build a lot of differentials the cheap ones on e-bay are not the one you want . they have a couple issues i did not like so i sent the one i bought back.
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Ill just find a new housing too
Might put that in the shop truck
Now question is. is the center section a body only ? Noticed it has a mount for a snubber
Might put that in the shop truck
Now question is. is the center section a body only ? Noticed it has a mount for a snubber
Any housing should work as complete units. Get a clutch sure grip. Repurpose or sell the one you have, or stash it away. I have 7 or 8 pumpkins with different ratios.
My shop truck has a 83/4
But no mount for a snub mount
Ill just look for a good 323 and add posi if I can't find one...or rear clutch it if I do ...i like doing stuff the first time . hate doing stuff twice
But no mount for a snub mount
Ill just look for a good 323 and add posi if I can't find one...or rear clutch it if I do ...i like doing stuff the first time . hate doing stuff twice
Sure Grip interchangeability
I have a clutch SG unit in a 489. If desired, does this unit fit into the 741 and 742 versions as well?
www.forabodiesonly.com
Dave999
Well-Known Member
the cone type work better in real world driving situations on greasy surfaces. is a torque biasing integral or seperated cone slip resistant differential
basically the cones are sacrificial part.
if the side gear and cone are integrated as one part...you have a problem when the cone is worn..new cone and case set is not available.
if the cone and side gear are seperate parts, and the cone sits outside of the side gear on the axle spline in the case, you can machine the ends of the cone down a few thou so the friction surface of the cone hits the case again and you put shims in between the gear and cone. Enough shim so that the cross or single shaft "just Just" seats in the respective case halves. or take out 2 thou of shim and have it tight... wear out quicker but more aggressive bias
either way you maintain spider to side gear mesh and all is well
this kind of rebuild is usually dismissed as a shoddy thing to do, possibly driven by people who have only encountered the integral cone version, that can't be rebuilt
but this is how all of the 5.5 inch to 8.8 inch borg warner axles in Australia and south africa were manufactured. If they needed shim on assembly they got shim from day 1 if they didn't, they didn't. The australian versions are supported for parts for the 7.6 inch 7.8 inch M76 M78.
and cones and side gears come in 25 28 and 32 spline axle which i think are SAE sizes
both types should have an oil vent/ window that shows the end of the cone and its distance from case end near the bearing mounting sections
if you can see a gap between cone end and case end face. near where the axles go...its a goodun
clutch plate version more aggressive, less good in mud, easier to rebuild, parts available, heavier, more parts to go wrong
me.... i just got torsen/ true track style centre and put all of my old diff centres on the shelf.... no more messing about.
only problem you have with them is a 2.77 2.92 3.23 3.5 :1 gear set has such a fat pinion head the tha "fat barrel" centre to the truetrac might rub on it, with the correct pinion depth setting in place. so you need to machine a few though off the rear facing face of the pinion, and of course then you lose the pinion depth info stamped into it...record that before machining to save wasting time later on messing about with spacers and shims
3.5 3.9 4.11 :1 small pinion head no problems
dave
basically the cones are sacrificial part.
if the side gear and cone are integrated as one part...you have a problem when the cone is worn..new cone and case set is not available.
if the cone and side gear are seperate parts, and the cone sits outside of the side gear on the axle spline in the case, you can machine the ends of the cone down a few thou so the friction surface of the cone hits the case again and you put shims in between the gear and cone. Enough shim so that the cross or single shaft "just Just" seats in the respective case halves. or take out 2 thou of shim and have it tight... wear out quicker but more aggressive bias
either way you maintain spider to side gear mesh and all is well
this kind of rebuild is usually dismissed as a shoddy thing to do, possibly driven by people who have only encountered the integral cone version, that can't be rebuilt
but this is how all of the 5.5 inch to 8.8 inch borg warner axles in Australia and south africa were manufactured. If they needed shim on assembly they got shim from day 1 if they didn't, they didn't. The australian versions are supported for parts for the 7.6 inch 7.8 inch M76 M78.
and cones and side gears come in 25 28 and 32 spline axle which i think are SAE sizes
both types should have an oil vent/ window that shows the end of the cone and its distance from case end near the bearing mounting sections
if you can see a gap between cone end and case end face. near where the axles go...its a goodun
clutch plate version more aggressive, less good in mud, easier to rebuild, parts available, heavier, more parts to go wrong
me.... i just got torsen/ true track style centre and put all of my old diff centres on the shelf.... no more messing about.
only problem you have with them is a 2.77 2.92 3.23 3.5 :1 gear set has such a fat pinion head the tha "fat barrel" centre to the truetrac might rub on it, with the correct pinion depth setting in place. so you need to machine a few though off the rear facing face of the pinion, and of course then you lose the pinion depth info stamped into it...record that before machining to save wasting time later on messing about with spacers and shims
3.5 3.9 4.11 :1 small pinion head no problems
dave
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@RustyRatRod used to re-machine and rebuild the cone style. I don't think he still does but it can be done. .
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