Lengthening Input Shaft on Transmission

admin

Hello All:Need help here from the pro's. I need to lengthen the input shaft on my 4spd manual transmission by about 3 inches. Plan is to have a professional weldor insert a piece of 1-1/8 diameter 4140 to accomplish this. I am unable to heat treat the finished item so that is why I chose 4140. Is it reasonable to have this attempted, I will provide a means of centering all three pieces but am not competent to do the welding. Would TIG be a good choice and any ballpark guesses at cost? Thanks to all for reading this and hoping to hear back. Take care.Burt
Reply:If it's going to see any "real" hp at all, I suspect it's going to wind up back in 3 pieces. Transmission input shafts are generally very stout material and I don't think I'd try to section one.What's your application? Why are you adding 3" to the input shaft (seems like a "bunch"). I used to work in tech support/sales for one of the major mail order parts retailers, maybe I can help?KevinHobart Handler 210Tweco Fabricator 181iLincoln Squarewave Tig 175
Reply:itll break right away..the original shaft is already hardened.....it wont take to the welding very well..or the torque. have one machined from billet..be alot cheaper
Reply:Without heat treatment, a piece of 4140 is not all that much 'better' than a piece of 1018.  Slightly, but not a whole lot.Next, if you can't heat treat it, how are you going to finsh machine it after the welding?How are you going to cut the splines?  Or were you somehow thinking that you would cut the existing shaft, and then weld in a splice to lengthen it?  Did you think of what that welding would do to the -existing- parts of the shaft, strength, hardness, and dimension wise?Next, what is the -specific- application?  HP, torque and rpm.How is the extra length going to be supported?Why don't you just get a longer input shaft instead of trying to 'make' one?  I'm all for DIY, but sometimes you just have to have get it done by the specialists.  The machine shop, the heat treater, etc in addition to a 'good' welder.I just don't see that sort of project/modification working out well at all.  The best laid schemes ... Gang oft agley ...
Reply:First off let me thank everyone who replied. My application is changing the engine in a Toyota Landcruiser from Stock 4.2L 6 cyl (125 HP / 250 LB-FT) to a 4.6L Ford SOHC V8 (215 HP / 250 LB-FT). Hope was to use the stock Toyota 4 spd Trans/Transfer Case witha Mustang T45 Bellhousing / Clutch / Flywheel and finally a GM 10.4" Friction Disc (to fit the splines on the existing input shaft). Need to make the input shaft of the Toyota Transmission longer to accommodate the Bellhousing and move engine forward a bit but not change driveshaft lengths. I do not really off-road the vehicle except when it snows here. Have been told that a proper weld is as good as the original material so that was my starting premise. Sounds like I need to scrap that plan and look at using the AOD-E transmission that is already attached to the 4.6L engine instead. Then only have to make an adapter and spud shaft to mate to the Transfer Case. Have a mill and a lathe so guess now the learning begins. Thanks again and take care. Burt
Reply:You could try  Advanced Adapters.
Reply:Originally Posted by fluvannabearFirst off let me thank everyone who replied. My application is changing the engine in a Toyota Landcruiser from Stock 4.2L 6 cyl (125 HP / 250 LB-FT) to a 4.6L Ford SOHC V8 . . .
Reply:Thanks for the replies. From all I have heard, looks like I have my work cut out for me. Going to have to think some more on this. Now for my responses to ekim and denrep.ekim: Have already contacted Advance Adapters and they don't make anything for either the Modular Series Engines (4.6, 5.4 and 6.8L) or the AODE Transmission. The closest thing is an adapter spud shaft ($214) that will match a C4 output spline to the 16 spline gear in the Transfer Case. Still have to make the adapter if I use the AODE, to hold the spud shaft and mate the two cases. Just wish I knew how to cut helical gears and involute splines since I don't think I can afford to have someone else do it. That is why I was trying to find out if I could have a piece welded into the middle of my existing input shaft to make all the dimensions come out.denrep: I am converting the engine to "old school" with a Carb (600 cfm Holley) and driving a distributor off the drivers side Camshaft. Need to make a replacement "bolt" for the cam gear that will act as an interface with the Distributor (289 Small Block Ford) shaft and a mounting bracket to hold the distributor using the mounting points for the Coil Pack that I won't need. The AODE can be converted to full manual shift with an available kit so won't need the computer. As for the width of the engine, it looks like it will fit but the battery will have to go in back. Otherwise new motor mounts (custom diy) and the fun begins.Take care. Burt
Reply:I'm lost on the the proposed drive, a 289 describler is probably a foot long. How 'bout a flat direct drive distributor, per aftermarket "crab" mag or dizzy made to fit '48 Ford type application.  But once a 4.6 loses its electronics and fuel system, won't it be a dud? After all it's only about 280 cubes and they're no torque monster.  I guess if you insist on carbureted Ford power wouldn't a  Windchester block  be the one to run?But anyway, can the wide-block 4.6 be crowded towards the cowl enough so that there's no need to lengthen the input shaft?Good LuckLast edited by denrep; 09-02-2010 at 07:17 PM.
Reply:denrep: Problem with the input shaft is that it is too short for the t45 bellhousing that mates to the 4.6. As to the distributor length, I plan to cut it down to just below the o-ring that way it won't hang out so far. Got it for $25 so might as well use it.  Don't know how the 4.6 will perform without FI but I have it and the AODE from an engine swap I did in my 93 crown vic. Put 98 short block, 01 heads and PI manifold along with T45 and am getting 219 HP at the rear wheels. Don't need much for the Landcruiser but always have the option of putting the computer back on it with pull your own parts. Guess that is about all I can say on the subject since it looks like lengthening the input shaft is a non starter. Thanks for the comments and take care. Burt
Reply:Well, if you insist on this "old school" technique, might as well win the Powerball while your at it.  It's gonna be expensive to make it work & won't work very well.How about just getting a MegaSquirt kit for your fuel injection & use the factory electronics of the engine.  No need for another computer, the MegaSquirt will run fuel & ignition.  Not a problem if the vehicle doesn't need a computer.  It's also a lot less expensive to build it yourself, that way you know how it works & how to fix it.Welding the input shaft of a transmission?  That's a fast way to have your right foot amputated when the shaft explodes.  Without any power adders in the engine.Last question is "why would you want to do this?"  It would be easier to just grab a SBF & drop in with an AOD behind it.  Less expensive too, although why move away from Toyota power plant to begin with baffles me too.MarkI haven't always been a nurse........Craftsman 12"x36" LatheEnco G-30B MillHobart Handler 175Lincoln WeldandPower 225 AC/DC G-7 CV/CCAdd a Foot Pedal to a Harbor Freight Chicago Electric 165A DC TIG PapaLion's Gate Build
Reply:MarkBall2: Thank you for your reply. 1. I have given the MegaSquirt system consideration but am not up for the expense and the programming needed I am trying to do this with what I have at minimal expense. 2.If you know someone who would swap straight up a 93 5.4 (351) SBF and AOD (or a SBC 350CID with 700R4) including all the frontend accessories for the 93 4.6L SOHC and AODE combination I certainly would entertain that if they were within reasonable driving distance. 3. I pretty well know how to fix a distributor/carb system as opposed to EFI. 4. Thank you for your concern about the welded input shaft,  I have given up on that approach. 5. As to changing out the 2F Toyota engine, it is tired and a rebuild would cost as much as a SBC  or   SBF.I will consider this thread closed unless someone else has something to add. Thank you all for your responses. This is why I asked the question in the first place. Go to where the experts are. Take care.Burt
Reply:I would suggest/suspect any auto recycling place would be able to provide either the 5.4/AOD or SBC/700R4 combo that might make a deal to swap the 4.6 SOHC engine/trans.  Might have to pay a little bit of money to make the deal, but the 4.6 SOHC engine is one many hot rodders are looking for.Said auto recycling place might also have a newer 2F Toyota engine/trans combo they could swap with you also.  Least expensive would be a used Toyota engine/trans.  That way you keep your old accy drive parts & it all bolts up without a lot of time & energy of fabricating everything.MarkI haven't always been a nurse........Craftsman 12"x36" LatheEnco G-30B MillHobart Handler 175Lincoln WeldandPower 225 AC/DC G-7 CV/CCAdd a Foot Pedal to a Harbor Freight Chicago Electric 165A DC TIG PapaLion's Gate Build
Reply:Thank you for those suggestions. Will look into that. Take care. Burt
Reply:Originally Posted by MarkBall2. . . the 4.6 SOHC engine is one many hot rodders are looking for. . . .
Reply:Originally Posted by denrepI know it's closing time, but...Maybe you're thinking of a double cam? This SOHC is just a workaday taxi engine; doesn't even have coil-on-plug ignition. Granted, still a very good engine.The other three combinations are all hot. I'll bet it'd be tough to find anyone to swap with credit  towards the 4.6, except maybe on paper.Good Luck