Mcnamara gear or factory gear/spacer mod?

[Spook50]

When I rebuild my tcase, I want to get rid of the infamous clunk that likes to manifest itself occasionally. I really don't have the cash monies to spend on the Mcnamara gear, so I was wondering of Doug's (dd113) gear & spacer welding trick is just as strong as the Mcnamara setup. It looks like all I'd have to do is set both the gear and spacer on a non worn section of the shaft so the splines would line up just right, and weld the suckers together. Any thoughts or input from people who've either done this or installed the Mcnamara gear? I looked around to see if Doug had posted actual instructions on how to do it, but no joy.

 

[baldredhead]

i think there are details if you search the yahoo 3fe archives, not sure if it's in the technical files or not

 

[Spook50]

i think there are details if you search the yahoo 3fe archives, not sure if it's in the technical files or not

Can't get into the 3FE archives. Haven't been a member for a long time.

 

[baldredhead]

oh boy, ummmmm

edit:

www.birfield.com

has some of the 3fe archives, the info might be there too. look for the archives link on the left

 

[Moby]

I've got the McNamara gear in my tcase and I feel good knowing it's there

 

[KLF]

Yeah I can't get into the 3FE archives. Had a squabble over a group purchase of some coolant filters a few years back with the then moderator and got myself banned. Never looked back.

Uhhh... yeah... whatever, Dan.

Still looking at kiddie porn?

(your friendly neighborhood 3FE list moderator)

 

[euclid]

OK, here's my thoughts.

I have the MacNamera gear on a brand new transmission output shaft (Extreme Transmission)... the best of both worlds. If it weren't for the slack in my 3rd member I'd have silent shifting.

Mix in the budget issues and I'd probably weld the spacer up, but I don't see how this could be as strong. A couple of problems that have come up in this discussion in the past.. one is that welding the gears will change the tempering of the steel because of heat, posibly makeing it weaker. Another issue is that the problem you are trying to solve is that the transfer input gear only engages the transmission output shaft over about a 1" space. Welding the gears and spacers means you begin relying more on the PTO gear to engage, which is even smaller than the origional input gear that is worn. The MacNamera gear replaces both gears and the spacer, and uses the entire 2.5" of output shaft.

DD113 is David not Doug. Might find more on a re-search. I have talked at length about this topic around the campfire with David.. we seem to agree that welding is a good trick, and will help it last a lot longer, but that the permanent fix is replacement of the input gear and that the best of all worlds fix is a new transmission output shaft and a new MacNamera type input gear.

Since you end up being the pioneer of all new solutions, how about finding someone to make a MacNamera type input gear here in the US for us? I bet you could sell 10 a year!

BTW, if you want to search the 3FE knowledge base you can do so on the birfield.com archives.

Hope that helps.

 

[Spook50]

OK, here's my thoughts.

I have the MacNamera gear on a brand new transmission output shaft (Extreme Transmission)... the best of both worlds. If it weren't for the slack in my 3rd member I'd have silent shifting.

Mix in the budget issues and I'd probably weld the spacer up, but I don't see how this could be as strong. A couple of problems that have come up in this discussion in the past.. one is that welding the gears will change the tempering of the steel because of heat, posibly makeing it weaker. Another issue is that the problem you are trying to solve is that the transfer input gear only engages the transmission output shaft over about a 1" space. Welding the gears and spacers means you begin relying more on the PTO gear to engage, which is even smaller than the origional input gear that is worn. The MacNamera gear replaces both gears and the spacer, and uses the entire 2.5" of output shaft.

DD113 is David not Doug. Might find more on a re-search. I have talked at length about this topic around the campfire with David.. we seem to agree that welding is a good trick, and will help it last a lot longer, but that the permanent fix is replacement of the input gear and that the best of all worlds fix is a new transmission output shaft and a new MacNamera type input gear.

Since you end up being the pioneer of all new solutions, how about finding someone to make a MacNamera type input gear here in the US for us? I bet you could sell 10 a year!

BTW, if you want to search the 3FE knowledge base you can do so on the birfield.com archives.

Hope that helps.

Yeah I meant to say David. I got a little dyslexic because I talk to a Doug on the Slant Six forum alot

Your thoughts ae pretty much the same as mine with the durability of the welding trick, changing the temper of the steel and wanting to replace the tranny's output shaft as the REAL solution. Having all the driving force on the smaller spline area of the PTO gear isn't exactly reassuring to me, though I'm sure it DOES last a long time (I know David wouldn't do it if he thought it was unsafe at all). I definately won't be getting my tranny rebuilt, since I plan to install an NV4500 at some point, and of course, that'll have a new output shaft (or the Advance Adapters kit has an adapter shaft, I can't remember how that worked out).

I'd love to find a local shop that could manufacture a fully splined input gear/spacer (don't need the PTO), but I think I'm pretty out of luck as far as that goes. It's lookin like the Mcnamara is going to be the say to go. I wonder if the 800 dollar Japanese gear (the one here ) is a higher quality steel or something, given it's way high price (hell for that and the rebuild kit, I'm not much lower than the price for an Atlas case).

 

[euclid]

Hadn't seen that option, probably because it's even more stupid expensive than the MacNamera.

 

[Spook50]

Hadn't seen that option, probably because it's even more stupid expensive than the MacNamera.

Yeah today was the first I'd heard of it. Must be some supersteel or some s***. The truck will be vaporized in a nuclear blast and the gear will survive, sitting on a small pile of ash...