Update on my 5.3L Gen III swap...

[JeepinPete]

I haven't posted up an update in awhile, simply because there was nothing really to tell. This summer got consumed by a rehab project on my old house

Anyway, I had some issues with the engine at first. Stuff like not wanting to idle, no power, etc. Turned out there was something in the bottom of the fuel tank that was plugging the fuel pickup I ended up installing an in-tank pump, since I had the tank down anyhow. Well, I am happy to report that the engine is running quite well now

So with that out of the way, it was time for a test drive. Unfortunately, that didn't go so well. Looks like the 4L60E trans ain't no good In low range it shifts just fine, but out on the road, it is dumping into neutral when it shifts into second gear. Not certain whether the trans is just worn out to begin with (everything looked fine when I changed the oil and filter), or something is gummed up do to it sitting for a couple years. I will report back when I figure this on out

[Walt]

Bummer. It sucks to get to a point where you think it's all down hill, just to find there is a whole other mountian range still to climb...

[shackwrrr]

I got a set of trans shift solenoids here you can have for 10 buck plus shipping. It could be your problem since these control your gears.I replaced them on a 4l60e once and it didnt fix the problem so i got 2 good ones here and I dont own the truck with that tranny anymore. And also I got a corvette servo that you can put in. It will firm up shifts and increase holding pressure. ill throw that in if you buy the solenoids. They are really easy to replace they are only a clip then unplug the wire then pull the solenoids then reverse to install. The servo I have detailed instructions for that. PM me if interested. There might be an auto tranny guru around that can tell you if these will help or not. For us it wasnt it was the sprag assembly. Ours it would act like it starts in 2nd then jump to 3rd and and then 4th but it was really soft and slipped the whole way. It happened when my mom decided to be nice and get gravel for my stepdad well 1600 lbs of gravel in an s10 in overdrive dont mix well

[Lindel]

Keep us informed Pete. I've got all the factory manuals for 03 if you need anything along that line.

[Sambo]

needs i say more

[pb]

If it helps, when I changed the filter & fluid on my 4l60e I accidently bumped one of the solenoid connections on the rear of the tranny with the pan and it came loose and screwed up the shifting on mine. I think I pulled the pan three times thinking I didn't have the filter & its seal in all of the way before I finally saw the wires half off.

[JeepinPete]

Sambo, there are plenty of pics, just check out the links in my sig to the three other threads...

pb, I will keep that in mind.

I am going to check over a few things with this tranny to see if I can get it working. If that fails, I am putting the TH400 guts into a chevy case and getting the Jeep back on the road.

Long term plans include going back to a OD tranny, but not the 4L60E. Not that I have any real issue with the tranny, but it and the QT don't really get along (front driveshaft clearance issues). I've been doing some research, and it seems that the 4L80E and TH400 back end are real darn close. It looks like the output shafts are close enough that I can swap a TH400 QT shaft into a 4L80E. The bolt pattern is the same, but I think the index diameter is a bit different. If all goes the way I am thinking, the QT will bolt up to the 4L80E without any adapters, just a little machine work. The 5.3L's computer will control the 4L80E just fine.

Here is a picture of a TH400 output shaft:



And a picture of a 4L80E output shaft:



Look mighty similar, don't they?

[shackwrrr]

I belive they are the same. a 4l80e is an electic th400 with overdrive. just like a 4l60e is the same as a 700r4

[JeepinPete]

The one thing I know is different is the area of the governor gear. Obviously the 4L80E doesn't have that gear. But it does have a seal that the TH400 doesn't appear to have. I wonder how necessary that seal is, since ultimately the trans is sealed by the transfer case. Worse comes to worse, I will make a ring that takes the place of the governor gear for the seal to run on.

[shackwrrr]

well if you put the tail housing and tail shaft on there wont that change the seal arangement too and make it work with the 400 shaft?

[JeepinPete]

That is more or less what I am thinking. The seal that I am refering to is in the actual tranny case, not the tailhousing. I am not sure why exactly GM added it. I am thinking that the TH400 didn't have one there because the governor gear needs the oil. Since the 4L80E doesn't have a governor, reducing the amount of oil back there would reduce leaks from the driveshaft on 4x2 versions. So using one with the QT wouldn't require that seal. I guess I won't really know until I take one apart and see for myself...

[JeepinPete]

Well, yet another change in plans. I just walked into a deal on a Chevy 5 speed and NP241 transfer case, all for $50. I wanted a manual to begin with, but wasn't going to pay the money that most get for them. So the auto and QT are coming out, and the parts to put them together will be up for sale. But since this is going to open a whole new can of worms, I ain't getting back on the road until spring, I am sure...

[Lindel]

And I'm still on the hunt for a 241. Good deal for you Pete.

Are you still planning on the motor mounts? Not in any rush, just curious.

[AlsChopShop]

Originally Posted by JeepinPete

I just walked into a deal on a Chevy 5 speed and NP241 transfer case, all for $50.

wow, great deal! is the 241 drivers drop or pass drop? i know they only came in pass drop in 89-91 suburbans and blazers so they are hard to find! ideally i'd like a 241 as well but i'm just happy i finally found a 350tbi to put in.

Al

[JeepinPete]

Its a drivers side drop. I have a ford D44 laying around, drivers drop, top mount spring pads. Seriously considering a SOA while I am at it. It has a 4" lift as is, not really looking to go any higher, just looking for a nicer ride.

Anyway, it isn't the bling bling NV4500, just a very early NV3500. Worked in a Chevy 1/2 ton, should work fine in the Cherokee:

[AlsChopShop]

that nv3500 will still be a decent unit. i'm sure it will hold up well in the cherokee.

i know what you mean with having to go SOA, i was planning to go that route but decided against it because 6-7 inches of lift is a bit too much for my needs. i really like the 4". you could always run the ford d44 spring under with your 4" springs, it would be less work welding the spring perches underneath than having to deal with all the steering changes.

Al

[AlsChopShop]

Originally Posted by shackwrrr

I belive they are the same. a 4l80e is an electic th400 with overdrive. just like a 4l60e is the same as a 700r4

not quite.

not all 700r4s are even the same. the earlier models were much weaker than later years, thus giving the 700r4 such a bad reputation.

the later 700r4 and 4l60 for all intents and purposes are the same, but the 4l60e is fully electronic. the only electronics on the 4l60 is the torque converter lockup control. ever rebuild one of each? the 4l60e is going to be about $400 more. i believe some internals did change when it went fully electronic.

while i'm not as knowledgable on the 400 and 4l80e, i'd be willing to bet they are very different animals. while they may share a few characteristics as being the heavy duty transmissions, the 4l80e having overdrive, full electronic control and different gear ratios... i would imagine the internal make up is very different as well.

Al

[JeepinPete]

No doubt on the steering changes. The problem is my 4" rides like a rock. I think it is about 1990's vintage. But it never sagged I'm really looking for that Cadillac ride that a stock Waggy has. After all, this isn't a cornering machine

As far as the TH400 and 4L80E, the gears are exactly the same, and are interchangeable. There are some additional clutches for the overdrive, and certainly the electronics, but mechanically they are very similar. Much more so that the 700R4 was to anything.

[shackwrrr]

whenever you feel like gettin rid of those springs put me first in line for them

[JeepinPete]

Well, I went and picked up the tranny over thanksgiving weekend. It is very good shape, all the gears feel smooth, input shaft is nice and tight, etc. The only possible issue is the transfer chain. There is a bit of slop in 4wd.

I pulled the 4L60E last week. It is now sitting in the corner gather dust.

The flywheel and clutch that came with the tranny won't work with the 5.3L. The Gen III small blocks use a different flywheel bolt pattern than a SBC. I picked up a '04 GTO clutch setup on ebay, primarily for the flywheel. The NV3500 pressure plate bolts up to the GTO flywheel (gotta love gm sometimes), so I intend to use a normal (read cheap) Chevy 12" truck clutch. The GTO flywheel is thinner, so I will have to use a different release bearing. Fortunately, GM has used five different length release bearings, so I should be able to find one to make up clutch height difference (again, gotta love gm).

If it warms up next week like they are saying, the new tranny should be bolted up next week. Then I have to fab up a mount for the clutch hydraulics, and maybe, just maybe I will have this thing back on the road (minus 4wd) before the end of year...