95 Tahoe

[mutlu]

Hello from Istanbul,
My new project is diesel convertion in my 95 Tahoe(350-4L60E-4x4).I have found a 6,2 engine here in a junkyard which came from a aircraft towing vehicle with its T400 transmission.Probaply engine year is 1988.I need some suggestions,
-Which transmission work easier in my conversion?And performance difference?
-Any specific parts do I need in this swapping which I have to get from junkyard?
-If I go to T400,I dont know which transfer case I have,does it work with my transfer case.

Thanks

[moondoggie]

Good Day!

Since no one else has answered

[mutlu]

Thanks Brian,

I can not find the control wiring and PCM for diesel here.Do you know any company for these parts in US except JET?

Please let me know,If you come to Istanbul.

[moondoggie]

Good Day!

I don't know, I'd never attempt a project like this myself. I'd guess the best place for these parts would be the salvage yard. Unfortunately, I'd bet you don't have lots of that kind of stuff where you are. :(

Blessings!

Brian Johnson, #5044

[DmaxMaverick]

Mutlu

Your best option for the tranny electronics is to obtain a stand-alone controller from Jet, or a like company. It will allow the tranny to operate like the older types without any need to talk to an outside computer (PCM/ECM). IIRC, they aren't that expensive and work well.

The 4L60 should do well with the 6.2L, even with a mild turbo. Kit it and it will hold up to a lot more. A healthy T-400 will handle just about anything a 6.2L can throw at it. The transfer case may not be compatible with the 400.

Either way, you will need a torque converter that is designed to operate with the 6.2L torque range. The gasser converters stall too high, although I know of some that have been used and they worked. I believe the early 4L60's torque converter were the same as the later 700R4's, which can be had for a Diesel, and are common here. The torque converter from the donor won't work, being for a 400.

[Mark Krieger]

I've got two Suburbans. One is a 2003 3/4 Ton and the other is a 1995 half-ton 2WD. I also have a retired USPS Stepvan with a 6.2L and TH400 and it's been running great. (78,000 Miles)

I'd love to keep the '95 Suburban and put the 6.2L in it from the stepvan. I can't imagine it'll be worth all of the work, but I'll be watching your progress and maybe I'll do the same.

I paid $3,000 for the entire stepvan. What's a good running 6.2L engine worth? Since an engineless stepvan will be worth alot less, I wonder how much I'll lose.

[moondoggie]

Good Day!

FYI, my daughter

[arveetek]

I have to disagree with you, Brian. No offense! I always appreciate your wonderfully worded comments! :cool:

I've been running a 1990 model 700R4 behind my 6.2L since 1996. I bought it used from a salvage yard, don't how many miles were on it then, but I've logged over a 100K miles since then. I use mine to regularly tow my 29' fifth-wheel. In fact, I just recently took an 1800 mile round trip to Colorado with my newly turbo'ed 6.2L. I've never had a single transmission problem.

I love the 700R4! I think it's a great transmission. In fact, I'll even go against the grain and tell you that I'm using a gasser torque converter! I actually like the higher stall speed, gets me moving quicker. My '86 Suburban that had a stock diesel 700R4 tranny was a real dog compared my pickup. I think the lower stall speed and the low shift points caused that.

Anyway, back to the original question: I would install the 6.2L and bolt it up to your existing transmission. The tranny you have is a good one, and will work just fine, even if you turbo the motor. I see no reason to change out the tranny and/or transfer case at this point. If you change to a different transmission, then the transfer case might have to be changed, and you know that both driveshafts will have to be modified, so why go through all the work and expense if you don't really need to?

I wouldn't even change the torque convertor if I was doing this conversion, but then, that's just me! :D

The only obstacle you will have to overcome is the computer controls. Going with Jet will likely be the easiest route. If it doesn't look like you will be able to get the electronic 4L60 working right, then I would probably install a regular 700R4/4L60 out of a 89-91 model...they're the best...and it will be a direct bolt-in without any other mods needed.

Good luck!

Casey

[jbell]

You'll need a 700r4/4l60e flexplate, the flexplate for the th400 that you currently have, won't bolt up to the 4l60 converter.

I swapped th400 out to go to 700r4, and am glad I did.

[mutlu]

Thanks,
DmaxMaverick I will try to contact with Jet,do you have any contact person email adress from Jet.Becouse I tried to contact several times from their web site,But they did not reply me.

Mark,Engine and T400 are about 3500 USD here(alternator,starter,pump,everything included).But I will need a serpentine belt frame kit.Odometre shows that engine has just 9000 miles.Who knows......

My biggest concern is about torque converter lock up function.I think PCM controls this unit in 4L60E.Is there anyone who uses BD`s torq-lock kit.Does this kit allow me to control lock-up and unlock manually?If it works manually,we`ll have another option to use 4L60E.We can apply a TRANSGO reprograming stick shift kit to exist tranny.

[moondoggie]

Good Day!

arveetek said,

[arveetek]

Originally posted by moondoggie:
.....it might help this fellow way over in Turkey, so he can make an informed decision.

Take offense? NEVER! At least not from reasonable folks like you & virtually everyone on the Page.

Blessings!

Brian Johnson, #5044 Amen!

Keep up the good work, Brian! :cool:

Casey

[mutlu]

Hello Freinds,

After your suggestions,I have gone to salvage yard today.And there is one 700R4 which comes from gas engine.Owner said that tranny is between 89-91 year.I have checked the tranny,there are 2 plugs on the tranny.One plug has 4 ways male exit,another is on the tale and has 2 ways male exit.Do you think that,can we use it without PCM/ECM?If yes,could you please tell me,how does it work shortly?And how does the lockup TC works in this tranny?

Thanks a lot

[jbell]

yes you can use this without computer, all it needs is 12volts to outside front (of four) pin, and depending on how it's internally wired, ground to 1 or both of the other 2 pins (should be one hole missing a pin on the rear inside) With both grounded you should get lockup in 2,3,4.

The rear 2 are for electronic speedo -- it's interchangeable with the 4l60 electronic sender you currently have (ratios between the two are probably different so you'll want to swap)

You will need: TV cable for 6.2/700r4, tvcable bracket (rare) the tv cable extension rod. You may also need to change the governor springs due to this being a gas 700r4. (if your shift points are off) The 700r4 shifts on governor (speed) and tv cable location only. The +12 is for lockup. You'll want to run the +12 to ingition switched power, and the ground through a break switch interrupt -- so that when you hit the brake it kills the lockup.

I just did this -- I'll look through my receipts and try to dig out the gm part numbers. It's kinda funky to see the tvcable bracket bolt to the back of the motor (same bolt as glow plug controller) and have a long extension rod go from the back of the engine, under the intake, and up to the injection pump. Once you take a good look at the injection pump location, it's obvious it has to be this way, there's no other place to hook up a cable reasonably.

If you don't swap transmissions often, a trick to get the converter to fully seat on the transmission is to: Place the converter on the shaft, most likely when you think is fully seated, it's not all the way in. Lift up on the center of the converter and give it a spin, in a revolution or two it'll go about another 1" onto the shaft and is now fully seated.

I have many 700r4 resources that I located before doing my th400-700r4 swap, let me know if you need any of them.

[mutlu]

Yes Jbell,you are right.The front pin has 4 hole but one of them is empty.If can you find the part numbers,it will be great for me.

I have got a TPS from my ex-6,2`s pump.But I never used it.I have seen some posts in the forum,which somebody use TPS in 700R4.What does TPS do in 700R4 system?
Thanks

[jbell]

Not sure on tps, I think it is a variable resistor that feeds a computer input that determines when / if to engage lockup function. In that case, all the computer did was to decide when the lockup should occur by applying +12. Since you want to be locked almost all the time, having a tps / computer is unnecessary, and I would ignore it

All you need is a brake interrupt,and a manual override on the lockup -- let the trans lockup in 2,3&4 for normal driving -- 700r4's have a TERRIBLE problem with heat / self destruction.

You keep it locked as much as possible and have a good cooler -- it'll run. (I've had early 80's experience with 700r4's--- not good, but I haven't found fault with 89 or later models)

The advise from this board that I followed was to put a switch on the dash that allowed me to defeat lockup for intown driving, as well as an indicator light that turns on when lockup is active. No lockup is very handy in 30-40 mph city driving. (ONLY!!)

[mutlu]

Thanks to everyone,

I have decided to buy the 700R4 instead of T400.So it means,I will have so much questions for you in the near future.I will buy the engine and tranny on this saturday but there is one interesting thing.I checked Injection Pump number and it is J coded but the number is 4410.I think engine is about 1985 year model.There is no any IP number like 4410 in Diesel page list.The engine comes from a military vehicle(aircraft towing vehicle).Can it be different number system for the military productions?