4l60e problems 94 Z-71 and removing tranny

Welcome!

By registering with us, you'll be able to discuss, share and private message with other members of our community.

SignUp Now!

georgewe4

New Member
Joined
Dec 17, 2004
Messages
539
I had 1st gear and overdrive fail in my 4l60e. I took it to a local tranny shop and he replaced two solenoids that were bad. He also advised me that there was a lot of cluch material in the filter. I went to his shop so he could show me how much was in the filter. He had taken the filter apart and there was a good heaping tablespoon of clutch material in the filter. The pieces were about the size of oatmeal. (my son loves oatmeal first thing to come to mind)
He advised me that the problem may not be fixed and I could have more problems by just replacing the solenoids and filter. My thing was it shifted perfect and then suddenly lost 1st and od. It started in 2nd and would shift to 3rd, then I could feel lock-up in 3rd. I was out of town when this happened so it was driven about 250 miles till I could get it looked at. I had him to just replace the solenoids with the filter. He called me later and told me it was fixedbut probably wouldnt last. I picked it up Friday night and drove it and noticed it seemed to shift softer. After about 10 miles it would go into overdrive, then lock up if I started to give it more gas in overdrive it would slip and the engine would rev till about 3500-4000 rpm then you could feel the trans grab and feel the truck pull up to speed. It also has a softer feel to it. So now I believe I'm looking at a tranny. It has 211,000 miles on it. I dont understand how it shifted fine and firm before the solenoid failures.

I am looking to remove the transmission myself, if its not a horrible job. I have removed and installed a tranny before in my Buick, and it honestly was'nt that bad. I am looking to do the same thing if I can. I am just worried about the transfer case or anything else that may add dificulty. I have looked on-line for instructions on how to do this. I have been able to find nothing. I'm sure someone here has done this. Any advice?
 
t case comes off easily...5 bolts i believe on an np208 case...slide the case off, and then remove the bellhousing bolts off just like a regular 700...
 
Its not to bad of a job. Remove the driveshafts the transfercase to trans 5 bolts in a star pattern. The trans will come over the Y pipe without removing but may be a little tight. Its easier if you support the engine from tilting back which should definately be done.


By the way I have a 94 GMC suburban with 205,000. The trans lost first gear. Just wore out. Also there is a part that breaks alot in the trans that you loose reverse. The builder was surprised mine was still living and always replaced them on rebuilds. I think it was a drum or shell???
 
The part that you are referring to is the sun gear shell. When it breaks you lose reverse, 2nd and 4th. There is an upgraded part available. Ask for "The Beast", odds are good they will replace it anyway.

The trans install is very straightforward if you have the proper tools and a lift and trans jack. Doing your first one on the ground may take a few hours. As stated before the t-case comes off with 6 bolts (s-10 has five) and it WILL come out of a 1/2 ton without messing with the torsion bars. It is possible to remove the converter bolts and ultimately the transmission without removing any exhaust, but if you are doing it on the ground with a floor jack you might think about pulling the exhaust down. It is a pretty tight squeeze and you have to put the tail of the trans basically against the floorboards. If the exhaust will come down without breaking the studs (not likely at that mileage) you would want to drop it to save the headaches. Be sure to install a new front seal in the transfer case as it is very common for them to get hard and let tranny fluid overfill the transfer case. Biggest issue there is the fact that you get low on trans fluid and don't see a leak. The trans shop will probably have some way of dealing with the debris in the radiator and you will need to follow their instructions on it. Some make you bring in the radiator to be flushed with a heated cooler flusher, some will give you an inline filter and some may just give you a can of spray to push through it. It's their warranty so do whatever they tell you to.

The good news is that the 93-94 model year are among the easiest to do. New enough not to have a detent cable, old enough not to have a (melted) external range switch and extra wiring to get in your way. If you want me to, I can list all of the bolt head sizes for you, I've done a few. Dozen.

bob
 
I must say I'm relieved to find out its not as horrible as I was thinking. I've never spent a lot of time under the truck to really take a look at things. I just want everything to work when I put it in 4 wheel drive. I am not that upset considering it lasted 211,000 miles. Especially with all of the towing the truck has done. I think I'm going to buy a replacement transmission. Ive been looking at several different places. One through e-bay. One that seems to be pretty good from the ad is this company eBay Store - Mad Dog Transmissions: 700R4, 4L60E, Turbo 350
I may call him tomorrow to talk to him.
George
 
Thanks

"INEEDAGN" I must have posted my last response about the same time you posted. Yes, if you wouldnt mind listing bolt sizes that would be great. Also the seal in the transfer case you are referring to. How hard is that to change, details on that if you wouldnt mind. Also what to ask for if I replace the seal. Is that a dealer item, or can I get it at an auto parts store?
Thanks all.
George

I talked to the guy at the link I posted (mad dog transmissions). He was very nice, very helpful, and very confident. He seems to know his stuff. I will let him know tomorrow. Its pretty nice. The tranny would be delivered to shop I work at, and he doesn't want my core back. The price given includes new converter and all with shipping. The only thing is-what am I going to do with a transmission that needs rebuilt?
 
sell it to a trannny shop for hard parts. They may act like its just junk but someparts inside are hard to come by if they were broken.


By the way bolts will be standard along the bell housing but all others will be meteric 10,13,15mm.
 
94 4l60E core is worth about $50 around here. Late model ones are the pricey ones.
The transfer case seal is easy, once you get the t case out of the truck, you remove 4 10mm headed screws, and pry the aluminum cover (which holds the seal) off the front with a screwdriver. knock the old seal out, press in a new one, and reattach using rtv silicone just like the factory did. Torque them to 12-15 ft. lbs. or so, actually the torque isn't that critical as long as it's somewhere between "loose" and "stripped". Only thing to be careful of is using too much RTV and accidentaly covering the lube hole with it. The aluminum piece is indexed and must be attached the same way but it's really easy to tell where the lube hole goes. I think the Napa number for the seal is 19255.

As stated most are metric except the driveshafts, bellhousing, and cooler lines.

Rear driveshaft: 7/16
Front shaft: 7/16 front, and i think 94 is still the old style flat flange in the rear which would be 5/8. Otherwise it's also 7/16.
Crossmember: 18mm with 18mm nut
mount: 15mm on both crossmember and trans sides
converter cover: 15mm
converter bolts: 15mm there's 3 of them
Transfer case to trans: 6 15mm bolts. leave the adapter on the trans.
Bellhousing bolts are studs with nuts on the end holding a bunch of brackets. nuts are 1/2 or 13mm, studs are 9/16. 6 of them, same as old 350s and such.
cooler lines: 1/2
exhaust heat shield if applicable: 10 or 13mm. don't remember when they changed that.
the shift linkage comes off with a basic cotter pin. There's a second one that, if not rusted in place, can be removed and allows you to take the whole linkage section off and out of your road. You probably have a manual t case and the linkage is just a plastic grommett that you can push out with pliers. might be hard as a rock so you might need a huge pliers. Most wiring should be obvious but there's a big plug in on the RH side that you remove by squeezing the big connector while pulling on it. squeeze it on the front and rear in relation to the truck. Wiring may have one or two 8mm bolts holding brackets on the trans. reach up and yank the rubber vent hose off the top and it can stay with the wiring. transfer case vent is held by a spring clamp.
02 sensors should be out of your way but there may be one or two you might want to remove to avoid damage, 7/8 wrench if you do

Nothing really needs to be torqued exact, It can be done by feel if you're a regular wrench turner. Keep in mind though that some fo them go into aluminum and it's not too forgiving.

I dont think I forgot anything but I am human.

bob
 
Lots of help here. I do really appreciate it. I am looking forward to getting this thing behind me. I called the company above and ordered the transmission. He assured me it would be built tough. Towing or whatever shouldn't be a problem. He assured me I will have no problems with it. I just hate spending the money. Ahhh, oh well.
The truck, Buick, and motorcycle share the same building behind the house. I will be sure to move the Buick out of the building while I do the swap.
When I replaced my first tranny in the Buick, the tranny dropped on my hand while under the car. I lost my temper somewhat and threw a wrench from under the car. It hit the wall, bounced back and hit the car. Needless to say I felt pretty bad after it happened. I have learned to keep my cool more better than back then. But.....just in case:smile:
It will probably be late next week before I get the transmission. I am on call the weekend of the 3rd of Feb. So it will probably be the following weekend before I do the swap. I will post how it goes. I REALLY appreciate all the help again. If anyone else reads this thread and has any advice. Please let me know. Thanks again.
George
 
Received the transmission today. Really impressed how well the transmission was crated and packaged. I opened the crate to look at the transmission. Painted very nice. It will be the nicest looking thing under the truck.
 
just a word of advise IF you remove the Y pipe replace the exhaust doughnuts. But myself I would support the oilpan and leave the exhaust in place. To drill the manifolds would be a worse job the the whole R&r of the trans.
 
Back
Top