I have a 4 speed (w/granny low) that is having issues with down shifting into 2nd and 1st ( I rarely use 1st). Instead of replacing the syncros, I am thinking of switching to a C-6 to reduce the strain on my universal joints. I have large tires on my truck (44" super swampers) and I think it wil be easier on my drive train to go with an auto. I want to eventually swap my axles to rockwells but for now, I have to take one step at a time. I think the first step should be to change my transmission. I haven’t changed the gear ratio in my axles. I will do that later when the rockwells arrive. I have stuck with the factory axle ratio for now. I have a pretty stout 400M that pulls quite well at low RPMs.
I'd appreciate some advise on what to look out for. Do y'all see any problems with swapping to an auto that I do not know of already. I plan to go with a LOKAR shifter; as I don't care for column shifters. I do like the look of a manual transmission.
Here is what I have identified so far as problem areas. I have to remove my clutch w/linkage. I have to consider a drop down linkage for passing gears. I worry about my transfer case linkage: I don't know if the new linkage will work. Please offer up ideas if you have them. If you can identify problems before I come across them, I will appreciate it; I want to minimize downtime.
if it were me I would leave the 4 speed until I put the rockwells under it. 44's and stock gears are very hard on an automatic you will probably burn the trans up from having the coverter in the stall zone all the time. when the converteris at stall that is when it makes the most heat and the most multiplication so it is blessing and a curse all in one. just my opinion.
If you swap in a C-6 you will have to lengthen your front driveshaft and shorten your rear driveshaft as the longer automatic will move the transfer case back a couple inches. You will need a different transfer case to trans adapter and as you suspected, a longer shift rod for the transfer case.
In my opinion, just replace the synchros in the 4-speed, and if you feel you need better u-joints, you will have to have driveshafts made anyway when you install the rockwells
__________________ '77 F-150 short bed,Dana 60 front factory coil spring suspension,Dana 60 rear 4.10 gears,460 with Holley 750, L&L fenderwell headers,150 shot NOS, ZF 5 speed trans,205 transfer case twin stick conversion,35 inch Boggers,sand scoops for the rear,onboard air,stainless Magnaflow exhaust
I haven't quite decided what to do now. I am considering sticking with the manual until I can go ahead with the rockwell axles. I do appreciate the advise.
Not only will you burn up a stock C-6 with 44's, but the second you put a shift kit in it youre gunna be hitting your U-joints way harder than with the 4 spd. Just my opinion.
I was going through them like crazy, about once a month, then I swapped all of them to Spicer universal joints. I haven't broken one since and that was almost three years and a few thousand miles ago. I highly recommend them to everyone.
I dont see how an automatic is going to be any easier on your drivetrain. If it's a manual 4-speed (whether it's a t-18 or np435) the first gear is unsynchronized, and can be hard to shift into unless you're in a full stop. Downshifting into it pretty much requires double clutching.
How much lift are you running? That probably has a lot more to do with your drivetrain problems than your transmission, especially with the 44s.
If you're going with rockwells, i'd definitely just stick with the manual 4-speed.
I actually just have a 3 inch body lift. The rest is stock for the highboy. The fenders are trimmed a little and that is all that was required to fit the tires I have. I can't go around flexing the suspension like those rock crawlers do, but that isn't what I do with this vehicle.
I actually just have a 3 inch body lift. The rest is stock for the highboy. The fenders are trimmed a little and that is all that was required to fit the tires I have. I can't go around flexing the suspension like those rock crawlers do, but that isn't what I do with this vehicle.
Oh...well i hate to break it to you, but with rockwells you're going to need quite a bit of suspension lift. Even with 6" lift most people have trouble with the chunk clearing an oil pan.
I don't have any advice for you? but I had to tell ya " I Dig that user name!"
Thanks, I found this forum while I was in the desert for the second time at Uncle Sam's request. It seemed fitting at the time. I doubt I'd have came up with it otherwise.
BTW, I'm sticking with the NP435 until I change the axles. I haven't found them yet locally but I keep hearing about a few people that have them. I will give up and have some shipped to Alaska if I don't find some soon.
just so you know, there is no such thing as a 400M. there is a 351M and a 400 but no 400M.
__________________
Kevin
1979 F100 4x2,
300 Inline 6,
3 speed manual,
9 inch rearend,
10 series Flowmaster,
Grant steering wheel,
JVC stereo in the glove box-the previous owner did that,
and some other stuff
"You got to drive that Ford like it's a stallion."-Jack Ingram & the Beat Up Ford Band
Transmission Swap
