McNamara shaft

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weak-link

weak-link

Joined
Jul 20, 2005
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Why replace the stock output shaft in a A440F with a McNamara shaft?

because of a clunk?

has anyone ever stripped the teeth on the stock shaft?
 
Thanks for this thread. I don't understand the McNamara shaft myself, so I look forward to someone who knows something to chime in.
 
The McGear is just that, a gear, not a shaft. The OEM shaft stays in place. The McGear replaces the transfer input gear and gives more of a purchase on the old shaft. I believe I have heard of someone fully stripping out the splines on the shaft, but I do not know who or where. I have personally seen several shafts that were worn more than halfway through the splines.

The clunk is caused by the massive torque :) of the mighty 3FE engaging. The splines and/or the gear wear and only get worse as the space opens and the clunk turns into a clang.

The OEM shaft stays in place because the only way to get it out is a complete tranny tear down. It is almost the last piece out on a tear down, and almost the first piece back in on reassembly.

Mitch
 
Unless he has come out with a new shaft I think you are talking about the McNamara transfer-case input gear. When the output shaft on the A440F develops sharp splines where the input gear sits in the t-case you run the risk of stripping the shaft or gear's splines so instead of changing the output shaft of the A440F, which I think would be one of the last things to come out of the tranny making it super labor intensive, you replace the PTO gear, spacer and input gear of the t-case with the McNamara gear which has a splined collar welded on to it so it can use the splines that are still good since we have no OEM PTO winches here in the states. The new output shaft for the A440F is around $370 and I don't know what the labor would be to rebuild the tranny. I would just replace the A440F with an H55 and not worry about it, but that is just me.:cheers:

weak-link said:
Why replace the stock output shaft in a A440F with a McNamara shaft?

because of a clunk?

has anyone ever stripped the teeth on the stock shaft?
Click to expand...
 
so are the teeth of the McNamara gear deeper or wider then the stock gear?

any one have picture of said gear?
 
I don't have a picture, but imagine a splined shaft welded onto the gear that would allow the gear to spline into the good splines under the PTO gear and spacer. Essentially lengthening the spline of the gear. Here is what the splines looked like after 300,000 miles on my 88 FJ-62. I had a vibration that would pulsate it seemed.

IMG_5665.JPG




EDIT: Fixed it for ya Steve.
weak-link said:
so are the teeth of the McNamara gear deeper or wider then the stock gear?

any one have picture of said gear?
Click to expand...
 
Last edited:
so your still going to end up with a clunk after a few thousand miles... right?

the stock shaft is soft and just going to do the same thing again just in another area...right?
 
Um, OK. Sure I guess...

The shaft on my own truck looked like the picture Andrew posted. It lasted 200k on the OEM configuration. I put 60k on the McGear with no clunk. So yeah, I guess a few thousand.

:D

Your only other course of action is to replace the shaft.

Mitch
 
Andrew,
Plusate? Is that a California thing? :cool:
 
overhanger said:
Andrew,
Plusate? Is that a California thing? :cool:
Click to expand...
Yes Steve, a California thing. We are in the 100s here so maybe the heat got to my head.:D I fixed it for ya.


weak-link said:
so your still going to end up with a clunk after a few thousand miles... right?

the stock shaft is soft and just going to do the same thing again just in another area...right?
Click to expand...

Like Mitch said it will last IMHO for at least 100,000 miles and you won't have to worry about stripping the splines in the middle of nowhere with basically no way to fix the problem. Also, when I rebuilt my t-case (new bearings and seals) and reused that shaft in the picture above, and the original T/C input gear I still had the PLUSATING vibration while accelerating, so when I opened it up again shortly after I noticed the sharp splines on the gear and the shaft above. I just ditched the A440F for an H55F, but that is my personal preferance. On long trips I have been getting 2-4 MPG higher than I did before even though the A440F has a higher (better) overdrive ratio. If I were a rich man I would buy the Rodney super tranny, with super valve body and super torque converter. Maybe some day....
 
Aseif007 said:
Yes Steve, a California thing. We are in the 100s here so maybe the heat got to my head.:D I fixed it for ya.




Like Mitch said it will last IMHO for at least 100,000 miles and you won't have to worry about stripping the splines in the middle of nowhere with basically no way to fix the problem. Also, when I rebuilt my t-case (new bearings and seals) and reused that shaft in the picture above, and the original T/C input gear I still had the PLUSATING vibration while accelerating, so when I opened it up again shortly after I noticed the sharp splines on the gear and the shaft above. I just ditched the A440F for an H55F, but that is my personal preferance. On long trips I have been getting 2-4 MPG higher than I did before even though the A440F has a higher (better) overdrive ratio. If I were a rich man I would buy the Rodney super tranny, with super valve body and super torque converter. Maybe some day....
Click to expand...

:grinpimp:
Come on back to Denver and drive one of those trucks you describe and bring your truck so I can drive the five speed! It's great to have two awesome transmission options for our old trucks. Chris, Front Range 4x4 is doing the H55F swap on his 62 so there are more of that flavor every day. Going to Moab soon to get some more serious wheeling time with the Extreme. So far I like it a bunch but this will be a great opportunity to find just how different it is from the stock A440F. Wheeling is really the main reason I stuck with the auto tranny. Mileage and power delivery has improved with the Extreme but not 2-4 mpg better. That rocks, Andrew! :cheers:
 
Google McNamara, they make lockers and other stuff. I believe they sell replacement shafts too. The sticks have the same problem and the gear increases surface area contact spreading the impact over a larger area and reduces wear, in my thinking the lubricants would absorb more impact as well, kind of like a bigger bearing on a crank would last longer on a high torque motor...
 
weak-link,

I HAVE stripped the splines on an A440 output shaft. To quote Daniel Edin(?), the owner and lead mechanic of Wemberley 4 Wheel, "That's a God awful sound ...."
The first time I heard it grinding (slipping), I thought that I had just spun a rear axle bearing. Went straight home and lifted the rear axle off the ground to find which side. No sound from the axle. I spent too much time chasing the problem (I hate to have others work on my vehicles). I finally asked around and was told by several that Wenberley 4 Wheel was the best in central TX. Daniel even had trouble tracing the problem. I then reminded him how it usually manifested it self when I was driving and Daniel called back about 20 minutes later, "That's a God awful sound when that thing starts". We only had about 172K on the Cruiser at that time.

That was about 5 yrs ago. That was before I heard about the McNamara gear or even Rodney's extreme rebuild. Before I even found MUD. We considered the available options and I went w/ an H42 4-speed swap. The H55f was just too much more at the time. I wish I had gone ahead and spent the additional money on the 5-speed, but the H42 is doing very well. I get at lease 25% better mileage over the A440 (about 15mpg) and the power and speed is so much better than the A440. I can't drive 80mpg w/ the H42, but then this is a Land Cruiser. But I can still drive 50 through the driving rain when all others are stopped on the side waiting for it to clear.

With the H42 tranny and 4.11 3rds on 31" tires, there is plenty of power to go up most highway hills. I'll be going to 33s for the next set. ".... Yes princess. I have to get bigger tires to make the speedometer work correctly ....":)
 
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