I am currently running a 727 trans with a NP208 transfercase. I was thinking of changing out the 727 for a AMC turbo400. I need to know if the 208 will bolt up to the 400 or do I need an adapter for it all to work. Or should I just stick with what I got now? Which setup is better for offroad?
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I know that Chevy use to have a NP208 behind the TH400 in some of their trucks but I'm not sure about swapping a NP208 from a 727 onto a TH400. I would think that an adaptor may be needed (I could be wrong though).
As far as which one is better for off road, they are both great. Both have the ability to be built up. I would leave the one that you have in there. -
stick with what you have. There will be a lot of changes to get the Th400 to use the NP208 (adapters, etc.), and it doesn't get you a lot of benefit. Plus, the Th400 is a horsepower drainer (takes a lot to turn it). And, the TF727 is not only a great transmission, you can rebuild it with a Transgo shift kit and buy some hemi clutch packs, and it'll be stronger than the Th400.Comment
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Great, thanks for the info. Also great to know that I currently have a good setup.Comment
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Well I agree with Ryan that the 727 is a good transmission; however, I will disagree in the fact that you should stick with it. Now I do not know if this was an option or not, but a guy I get parts from just recently sold a Turbo 400 that he claims was in an 80's J20 that did have the proper NP adapter. I saw the trans with my own eyes and I was in disbelief until I saw it, but I will say they are out there. The 400 may take a little more power to turn that the 727 but not by much if any a difference. You gotta remember the 727 has an extra drum and sunshell on the 400 if my memory serves me right. The 727 is a durable transmission, but the way their pumps are circuited and set up hve very little to be desired, along with their TV Cable. The electric kickdown solenoid on the 400 is way faster. Did you know that when the 727 is in park fluid does not flow through the transmission at all? That is why after not driving your rig for a while and then you hope in and drive the trans feels like it slips. Factory specs 400s are capable of handling up to 550 Ft Lbs of torque so most hot rodders and transmission guys just rebuild them with factory parts because of how hardy they are originally, not to mention all you gotta do it remove the wave plates and a few one-way check balls to make those clutch packs fill up faster which gives you a much firmer and faster shift, just like a shift kit would. I'm not saying the 727 is a bad transmission, but I will say just think about how you want to invest your money.Comment
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The TH400 does take more hp to run than the 727, and it is a noticeable difference. Also, to run any 80's-up tcase beside the Th400, you'd need to change the output shaft and adapter, plus driveshaft changes / etc. The TF727 was used for many years by hotrodders and drag racers with minor changes, and holds gobs of power. Install a shift kit and a diesel drum in it, and you have a trans that will easily handle 800-900lb ft of torque. You are looking at $50-60 for the shift kit, and $100 for the drum, plus around $650 for a bench build. AND, no other changes required. That is why the 727 would be better to keep, as nothing else has to change outside, saving both time and money.Comment
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Ryan there are Turbo400s already with the correct output shaft and adapter. I am very unclear as to what Jeeps they came out of, but there are out there. I could have bought one for my Truck. The guy who was selling it told me it came out of an 80s 1 ton J20. He claims they were an option. I would think the 400 from the Commandos with the 304 would be a go because they had dana 20s behind them. Yea the 400 takes up a little juice, but its bigger, heavier, and a lot more reliable than the 727. Not to mention the electronic kickdown is much faster and smoother than the 727s ancient tv linkage. The 727 is a slushbox for a transmission. Weigh the pros and cons. For the little more power it takes to turn, you get a much more reliable transmission, much more reliable pump, a much crisper shift, and you still get the torque multiplication, plus the 400 is a lot cheaper to rebuild and mods such as different ratio planetaries is an option.Comment
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the TH400 wasn't used after 1979 in FSJ's, as they switched all the Jeeps over to TF727's. Not sure where the guy that sold to you got his info, but there is a lot of literature to support the 727's being exclusive as the auto.
The 727 is a very reliable trans, and with a shift kit and diesel clutch packs, they hold well over 800hp (you can do a google search for how many professional drag racers use that trans). The TV linkage is great as long as you take the time to set it up properly (same reason the 700r4 used it). For the rebuild of a TH400 vs TF727, the bench build price is within $100 around here.
Having said that, the TH400 is a great transmission, but having run both over the last decade + in FSJ's, I'd take the 727 over the 400 any day. Plus, with the 727 you have a host of options for tcases (208, 219, 228, 229 & Dana 300) that are all bolt-on without any special changes or adapters. The 66-72 TH400 had the D20, but all 73-79 TH400's output is only set up for the QT.Comment
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I personally like the TH400 better than the 727 mostly because it doesn't have a messed up kick-down linkage. On a TF727, if you don't have the kick down adjusted properly or if it falls off you will destroy the transmission. On a TH400, the kickdown is vacuum actuated and the passing gear is electric and if it stops working it will not destroy the transmission.
The TH400 is a power hog but it is very strong.
I do like the adaptability of the 727 for a transfer case right out of the box though.Comment
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Ryan I had done some digging on that 400 and I never found anything either that was just what he told me. My point is stock to stock the 400 is still a much stronger transmission. But it is heavier as are the parts inside. For most rigs out there a 400 won't even need modifications like the 727 would. The 400 is built to handle 550 ft lbs of torque. Yea drag racers will use a 727 in their (mopar) cars because its the best trans that chrysler offered. Beefier than a 904 and so on, but a 400 all you have to do is get a factory set of frictions, replace the wave plates with steels, and remove a few check balls and you are ready to go! The 700r4 ran the TV linkage because the 700 is essentially a turbo 350 with overdrive, which also had the tv linkage setup. If you noticed the later 700r4, or 4l60E did not have a tv linkage setup at all. I find the auto adjusting band in the 400 to be much better than the double band setup in the 727. Not to mention 727s have a issue with the band linings to just fall off the band. An issue I'm possibly dealing with right nowComment
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