AT1545 thread

[Booyah45828]

Did stuart/stevenson say anything or did you not tell them what they came up with was wrong? I'd say if they have access to allison files, they'll be your best bet.


Not to highjack, but there's two more of these transmissions for sale on govliquidation. Both located in CO. One looks used to me but the other might be new/reman. Do your due diligence before purchasing.

Allison Transmission DIV. OF General Motor Corp. MDL AT1545P transmission. SN. 3210982628. Shipping dim 46"x35&q... - Government Liquidation

Allison Transmission DIV. OF General Motor Corp. MDL AT1545P transmission. SN. 3210802672. Shipping dim 46"x35&q... - Government Liquidation

[turf]

i've reached back out to stuart stevenson and am awaiting a reply.

here is a link worth sharing, AT500, AT1500 service manual.

http://docshare01.docshare.tips/file.../283760640.pdf

still poking around the internet on my own, i found this flex plate for AT1545/3116cat

https://www.allisontransmissionpart..../23049018.html

still not right.....
this too

http://www.tonkinonlineparts.com/sho...ssembly=827178

i'll wait a couple of days to see if i hear back from some of these parts guys, but im begining to think the one off cnc route is the way to go.

[turf]

question:

can i modify (drill holes) my flex plate?

if i just got a 3/8th" ring with the holes to match the TC, i could drill new holes in the flex plate where the TC holes line up.

[cadillackid]

In my opinion I don't see why not. But you need to be exact! So that the converter spins on center and balance.
I'm assuming it's a different diameter bolt circle ?

The new ring you got? Did the converter still stick out too far? Or the engine bolt circle too big?
Christopher

[turf]

the bolt circles are to big. same center hole, first row of holes is about half a hole off, second round of holes is a full hole off.

pictures on post #60
http://www.skoolie.net/forums/f33/at...tml#post216099

the width of the plate, which i did not take a pic of still left the total length of the transmission about 1/8" short. a washer would have been the ticket.

[cadillackid]

When you say an 18 short, how far are you accounting that the converter will be pulled forward if it's full pushed back position. You don't run your converter fully slammed into the transmission. Everything I've ever built you had a 1/4 - 1/2 inch that you pulled the converter forward toward the engine to bolt it up.
Christopher

[turf]

the spec in the manual gives a range... to keep it simple im going to do metric.

books says 81-86mm

TC fully installed plus that ford plate is right at 78mm sticking out from the flange.

[Booyah45828]

If the holes not lining up was the only issue, I'd say drill the flexplate for the converter. But you are, like you measured, 81-88mm out even with drilling. Will the ford adapter bolt to your flexplate at all, or is it too big as well?

[turf]

i'll get under there today and look. if i need to, i'll pull the flex plate out.

no, my first instinct says the flex plate won't fit, at least not into the original holes.
the outer ring (flexplate side) is about a hole off,
the inner ring (TC side) is half a hole off.

neither ring lines up with any premade holes, the spacing and size of the holes is right, the diameter of each circle is to big.

[turf]

i took the flexplate off

here are some pics, measured from the same spot.

i think i'm going to take this down to the machine shop and see if they can make a ring spacer and drill holes in the flexplate.

the original plate @ 8.125"



the new TC @ 7.5"



the spacer - .625" or 5/8"ths

sound right?

[Kubla]

I got lucky today, got a technical diagram from an Allison distributor showing all the parts needed to bolt an MT643 to a TE444, do not know how to post a PDF to this forum since I do not think I can put it on my smugmug page

[cadillackid]

that number seems off unless you are giving totals.. but you want some play in that converter.. you posted like 81-88mm? seems right that its little less than 1/2 inch to move out from slammed in.. so you have to allow for that while you are on the ground..

if you has washers that were correct thickness , I dont see why you couldnt use them fron torque converter to ring.. you are using thread lock on the bolts.. i might tack weld each one just enough so it cant work out from centrifical force.. but you really have to pay attention to balance... (when adding metal it has to be across the board)
-Christopher

[turf]

i took the parts over to a transmission shop to ask their advice / see if they had a contact for adapters. they don't.

his advice was to use spacers and drill the flexplate. so next stop was a machine shop. i should have some spacers and a drilled plate monday.

the trans guy said as long as it was tight, should be no problem.

[Booyah45828]

Got an update?

[turf]

the flexplate and converters are still at the machine shop. i thought i'd hear yesterday to come pick them up but.... nothing yet.

i'm planning help to get the trans re installed this saturday.

the install manual has "guide tool" to make out of an M10 bolt. yesterday i ground off the hex head from the bolt to make the tool. fwiw, don't get the hard grade 8, that took some time with my little grinder.

[turf]

Kubla - i started using "dropbox" for pdf's and large files to share. it seems straight forward and easy. i bet someone wants to see that t444 info!!


i got the spacers back from the machine shop. ready for the weekend mechanic.

the spacers will be blind when they go on, so i'm gluing them in place.




and mocked up:

[turf]

i don't think the speedometer is going to work.

i can see how to change gears from the service manual, but it'd be destructive and set me back a couple of weeks ordering new seals and bearings.
so......

the 545 has a speedo gear that is parallel to the hole. if you look close you can make it out here



the 1545 speedo gear is perpendicular to the hole, it looks like it would drive a mecanical speedo, not an electric one.



i took the electric speedo sensor out of the 545 and put it in the hole in the 1545 anyway.

same with the neutral start switch. the 1545 had one and 545 did not. so i took it out and plugged the hole with the plug from the 545.

probably the wrong speedo sensor installed



and the neutral safety switch removed and plugged.

[JA Savage]

Man you are going through a ton of sh*t with this trany replacement we hope it works out for you and that you will be on the road in no time.

[turf]

thanks John!

i hope to get it finished in a day or so..... (famous last words , eh?)

I'm going to make the Nebraska trip for the eclipse next week, in the bus preferably!



here is the flex plate back installed with the spacers and new holes drilled.

after picking up the spacer from the machine shop, i never measured how long they were. i just trust the machine shop to have measured right. eyeballing them, they are about a half inch.



and this is as far as i can get before i need some muscle. hoping its buttoned up tomorrow pm. the trans needs to go over axle and then straight forward into the engine.

i'll probably put the deep pan from the old trans back on this, but i thought install would be easier with the shallow pan.

[cadillackid]

so the 1545 came with a speed sensor? or not? on my 545 the speed sender doesnt make contact with the speedo gear... its magnetic.. is peropendicular or parallel if it sees metal going be enough it should pick up pulses.. on mine its a weak AC signal. with the plug in there as long as it doesnt make contact with the gear nothing will break.

place a Digital multi-meter in AC volts across the 2 speed sender wires.. put the yoke on, rotate the tail shaft.. if you see voltage on the meter while rotating then you are getting a signal. if not then theres no signal.

as a reference you can do the same with the old AT545 as a baseline for what you should see.

if you get any signal at all, then you can place a dab of nail polish on that gear inside the 1545.. rotate the tailshaft exactly 1 turn, and count how many gear teeth pass by.. if its 16.. then its hook it up and be done.. if its not 16 then you'll likely need a Dakota SGI-5E speed signal converter..

if you get no signal whatsoever then its either dismantle and install the 16 tooth reluctor wheen into the trans.. or get a cable driven speedo gear, a transducer, and the dakota box.. more complex and more pricey if this option has to be taken..

-Christopher