Spicer 5 Speed in an A3

[m-35tom]

the a3 with a 3116 cat is a #2 with an adaptor ring to #3, so the 3053 would bolt right in. someone should do this swap, it looks quite easy once you find a flywheel. gerhard, since the cat and the multifuel are both sae #2, is the flywheel really that different?

 

[gringeltaube]

Both engines come with a (nominal) 17" flywheel (ring gear O.D. = 17.5"), depending application. Everything else looks different, though.

According to the book, only A3's coming with the AT-545 transmission have a real flywheel (#161-9068, pics below) which I think could be drilled to accept a 14" pressure plate. Or swapped for one that already has the clutch mounting bolt holes.

What I would like to know (can someone please measure...?) is the distance from that flywheel surface to the rear face of the adapter ring (#12); the surface where the tranny mounts to. Having that dimension it would be real easy for me to "paint" the Spicer behind that Cat and see how it works out.


G.

 

[spicergear]

On a spicer 3053A you are looking at a .85 5th gear ratio compared to a .75 in the B model.

Spicer 3053A
1st 6.00
2nd 3.31
3rd 1.89
4th 1.00
5th .85

3053B
1st 4.50
2nd 2.50
3rd 1.50
4th 1.00
5th .75

3053B is a myth just like the .85 overdrive. I could have sworn I saw a 'B' one time...maybe in the plethora of 3053/3052's I've looked at along the way...but went back and couldn't find it. M35Tom's overdrive it gives you new parts, updated transmission tricks, and a better overdrive!

 

[spicergear]

I also don't understand why bother listing non overdrive auto or manual transmissions?! Who want's to be stuck at the lower speed? It's no gain over the factory non OD four speed. If you're going to go through ALL the hassle to swap out, at least do it for a reason.

 

[m-35tom]

G, i still want to see a comparason of the cat flywheel vs the multifuel. i assume different bolt pattern, but you never know, some things have a standard. or could it be redrilled?
tom

 

[goodguyzy]

Ive got every thing to do the conversion, except skill and time.

 

[spicergear]

Both engines come with a (nominal) 17" flywheel (ring gear O.D. = 17.5"), depending application. Everything else looks different, though.

According to the book, only A3's coming with the AT-545 transmission have a real flywheel (#161-9068, pics below) which I think could be drilled to accept a 14" pressure plate. Or swapped for one that already has the clutch mounting bolt holes.

What I would like to know (can someone please measure...?) is the distance from that flywheel surface to the rear face of the adapter ring (#12); the surface where the tranny mounts to. Having that dimension it would be real easy for me to "paint" the Spicer behind that Cat and see how it works out.

G.

Is a 14" pressure plate used for the standard deuce clutch discs? Asking because the deuce has the 13" clutch and my 1160 CAT had a 13" clutch so that would give even more room on that A3 flywheel plus if extra clutch strength was needed, the CAT came through with the multi-disc spacer for the a pair of 13's.

 

[gringeltaube]

No, I was just thinking ahead when I said 14"...

For the 2.5ton MF it still is a 13" PP with the popular 5-pad disk, 13"nominal.
Measured over pads it actually has 12-5/8" O.D. and 8-1/4" I.D. = 72 sq in swept area. Compared to other mid-size truck applications this is not really impressive for my taste, especially if we wanted to go a little higher on engine torque.

I'm not sure if a 14" PP would fit for this particular conversion; that's why I needed the Cat's measurements for a little drawing...

For reference, I did manage to install such a 14" clutch behind a Cummins 6BT w/ SAE#2 housing, and then hooked up the Spicer 3053 via #2->#3 adapter ring. Throwout mechanism & bearing remained stock M35.
It's a close fit but it worked out well without having to spend much more for a twin-disk clutch. And that 13-3/4"O.D./ 7-1/4"I.D. soft disk still gives almost 50% greater swept area, besides much smoother clutch operation.

G.

 

[gringeltaube]

G, i still want to see a comparason of the cat flywheel vs the multifuel. i assume different bolt pattern, but you never know, some things have a standard. or could it be redrilled?
tom

Me too; wishing I had one (#161-9068 ) on hand to take some measurements... Googled the net up and down trying to find any specs, but no luck so far.

Attached is a small drawing with all relevant dims. for the 2.5ton MF flywheel, to start with something at least.

Also; first soldier with an A3 having to pull his AT-545: PLEASE measure distance from flywheel to adapter ring rear face.
That would be distance "D" (in red, 2nd drawing) which is 2.28" for the Multifuel.

G.