Slant Six Forum

I know this concept isn't popular, but OD automatic question
Page 1 of 1

Author:  Christian Nelson [ Fri Dec 10, 2010 10:49 am ]
Post subject:  I know this concept isn't popular, but OD automatic question


I am in the process of rebuilding the tranny for my wife's Suburban. While at it, I will be strengthening the 2-3 clutch weakness, and fixing the sloppy valve body issue that causes the slippage there.

I have it on my bench, and I am looking at it..

I've been thinking of doing the T-5 5 speed in my 74 valiant. I was going to go the route, where I put a 4 speed bell housing on it, redrilling the holes, etc.. But have been reluctant due to the cutting of the floor, etc..

Well, I am thinking about this, while looking at my 4L60E on my bench, and noting that I need to take the bell housing off, then, it hits me..

What if I were to get one of these, and figure out how to mount a manual bell housing on it, and then figure out how to attach the torque converter to the flex plate, etc.. This might just be easier than the work of doing the T5..

Now, this does not address the electronic shifting how it will be done, etc, but I thought this might be something to pursue in some other day when i have time.. If nothing else, one could do an electronic paddle shift setup if needed.

Had anyone looked into this?

I know Keissler makes bell housings for 4l60e's but that is for v8..

Does anyone see any obvious issues (measurement wise) here that might make it not viable? Not looking for Mopar guys who wanna spit on GM tranny (especially being that a T5 upgrade seems acceptable here) I just did not find this specifically thought about in my searching.

flex plate on Gm's has the starter teeth, whereas the Mopar has the teeth on the torque converter, any other obstacles here?

Author:  olafla [ Fri Dec 10, 2010 11:34 am ]
Post subject: 

Hi Christian.
The subject has been debated earlier, if you use the search function and make 3 separate searches, one for '700r4', one for '4l60e', and one for 'transmission adapter', you will find some of the threads about adapters that also cover the GM autos.

There are many of us that wish for a GM/SL6 adapter from Keissler or others! Some Mopars produced in South America were equipped with GM manual gearboxes and also local versions of GM rear axles. I have Motorcraft carburetor, GM alternator and GM HEI ignition with a Ford type coil for my car, and couldn't care less about what manufacturer's parts that do the job, but I would prefer a Mopar version if it is the best, and still available. After all, our cars are getting older and harder to find parts for. Unless you are restoring to original state; if it fits and if it works - use it!


Author:  Christian Nelson [ Fri Dec 10, 2010 12:16 pm ]
Post subject: 

The subject has been debated earlier, if you use the search function and make 3 separate searches, one for '700r4', one for '4l60e', and one for 'transmission adapter', you will find some of the threads about adapters that also cover the GM autos.

I did see that, but that was not speaking of what I am speaking of. Those threads are refering to bolting an adapter to the bellhousing..

I am talking about taking the bell housing off, on a later model 4L60E (which have a removable bell housing) and using a /6 manual transmission bell housing like a few have done for a T5, bolting it onto the front of one of these, that way you would not need to purchase any adapter from keissler..

It seemed to me the biggest issue that was had with using a GM tranny (other than the peeyeew GM sucks, yuck posts) was the need for this adapter, which cost $$, and moved your starter out where the exhaust would hit it.

Now, will the 4L60E torque converter fit inside the /6 manual bell housing would be another question too, but I did not find this specific thought brought up in my searching. This is taking the REMOVABLE bell housing off the later model 4L60E's and installing a /6 manual bell housing in it's place by grinding/drilling holes til it works out, like is done with the T5..

Thank you for the response though. I am thinking about this, and even the torque converter being too big could be worked around by installing a circle track type solid shaft to it, and use the pump as a clutch, you'd have basically an electronic manual transmission that would not molest the body of the car..

Author:  sandy in BC [ Fri Dec 10, 2010 1:35 pm ]
Post subject: 

The big deal on any trans swap is the cross member / torsion bar mount.

You will have to deal with cutting the floor with the 4L60E swap as well.

If you are desperate for an OD auto try a A500 with a dfactory will still have to cut the floor and make big cross member changes.

If cutting the floor is in your way have few choices.

Author:  slantzilla [ Fri Dec 10, 2010 2:56 pm ]
Post subject: 

I'm trying to understand why anyone would want to swap a freaking 4L60E into anything? :?

I have one in my GTO and so far have been relatively underwhelmed with it. The one good thing I can say is that it hasn't broken.......................................................................................................................................................................................................yet. :shock:

Author:  turboram [ Fri Dec 10, 2010 3:33 pm ]
Post subject: 

you can build an a518 to hold way more torque than the overly complicated 4l60e ,but I will say I like the 4l60 I rebuild a lot of them more $$$ for me :lol: :lol: :lol:

Author:  olafla [ Fri Dec 10, 2010 3:38 pm ]
Post subject: 

There are several threads dealing with an aftermarket bellhousing for mounting a GM auto to a SL6. When referring to an adapter between a SL6 and a GM automatic gerarbox that has a separate bellhousing, we usually talk about a bellhousing. By reworking a SL6 manual trans bellhousing to fit a 4L60E auto, you are actually making an adapter.


Author:  DusterIdiot [ Fri Dec 10, 2010 5:56 pm ]
Post subject:  Lol...

Some Mopars produced in South America were equipped with GM manual gearboxes

That's OK, GM put a lot of A-833's behind GM trucks in the 70's-80's...LOL


Author:  Christian Nelson [ Mon Dec 13, 2010 6:00 am ]
Post subject: 

I am not DESPERATE for an OD auto, I want OD, and what came in this car is an AUTO, so I figured finding a way to put an auto with OD might involve a bit less cutting of the floor pan out than the 3 speed with OD (I had tried that one, but realized that I'd have to cut out the floor all the way along the side of the tranny and was worried it would weaken the body quite a bit doing so- this was years ago, before I knew about the options there are available, but anyways I ended up scrapping- YES SCRAPPING UGH! the 3 speed with OD and putting another crappy auto in it that failed within a few weeks, belching tranny fluid out the front seal) I would love to have that setup back again, but I doubt I can afford to buy it, and there aren't many U-pull junk yards with 1970's Aspen's around nowadays I can pull it all out of again. I'd need clutch and brake pedals again (I never did figure out how to make the brake booster work correctly with the brake pedal setup, it wouldn't push all the way, I was 17, and didn't have much fabrication skills at the time) so I thought putting in an auto would be simpler, and work with the body and so forth a bit better.

I am not in love with the 4L60E, but I have one sitting on my bench, and looked at it, and saw some potential, wondered if anyone had done this.

The transmission adapters on the bellhousings move the starter where it would interfere with my exhaust, is what I've heard, plus I have no idea where to get one, and they are potentially prohibitively expensive? I don't know.. I like the looks of the A500, if I could get one in there..

I don't mind the idea of cutting the crossmember (mine drops out, and can be replaced) not sure why I would need to cut the floor for an auto? Is there something sticking up, or what?

I really like the idea of the 5 speed manual, but it looks like a BUNCH of fabricating, not just to get the tranny to fit, but the hyrdaulic clutch, or the linkage, with the brakes, etc, then I still have to cut a hole (though not as big as the one for the 3 speed with OD, so not too bad) truth be told, I'd rather do that, but not sure which is more likely to succeed. Bottom line, I want whatever I end up doing to be able to be completed, and have a driving car, not something I will get hung up on, and end up letting sit for years because of that, and giving up. I really would like to get this car going again.

Right now, the car has a 727. I think either that tranny sucks, or I have something wrong with the rest of my car, because I went through something like 4 transmissions on that thing in the 3 years I drove it. It was my main motivation for going to stick. The final one made me just give up, and I almost junked the car. I decided to keep it, because it was my first car, and my birth year, and rust free in our area. Now, I've been told, well you got a junk yard tranny it was probably junk to begin with.. But, I got 4 of them!! I've pulled trannys out of GM's and put them in GM vehicles, and they just worked, for years! Why did 4 in a row go for like a year, or six months, then just slip, lose reverse, or begin belching fluid everywhere? So I am wondering if my coolling lines have a problem, but I did blow them out with air, so they weren't plugged, and I wasn't getting water in the tranny fluid from what I could tell, not sure what else it could have been, for this reputation the 727 had of being a big rock solid tranny, I didn't find it so.

Anyhow, the reason I looked at this tranny (the 4L60E) in particular was the removable bell housing, does the newer A500's have a removable bell housing as well?

Where would I even get an adapter for the autos from a v8? Do newer V6 engines with that same tranny have a similar adapter?

Thank you all.

Author:  Christian Nelson [ Mon Dec 13, 2010 8:37 am ]
Post subject: 

I should probably also note that my dad just thinks I should just rebuild the 727, and put it back in, taking my time to do it right, and just drive it like it was meant to be..

I suppose that wouldn't be a real problem, thing used to get close to 20 mpg before, and I never felt like I couldn't keep up with traffic or anything.

Ugh, descisions..

I have time to think more about this and put together parts, it's not like the car is going anywhere. I just want to have a good plan when I DO start on it. ONe thing for sure, I am sand blasting, and duracoating the whole underside. I am so sick and tired of rust eating up every other car I have owned.. Not this one!!!

Author:  slantzilla [ Mon Dec 13, 2010 2:34 pm ]
Post subject: 

If you're killing 727's, a 4L60E is NOT for you.

Author:  olafla [ Mon Dec 13, 2010 4:50 pm ]
Post subject: 

Hi Christian. If you want better milage, I suggest you try finding a good 904 with lockup (77/78 -> up), and do like you dad says. Look through the threads for modifications and adjustments, and rebuild it like it should be for your use. If you don't need any performance shift kits, at least get a shift correction kit (for better flow, adjusting shift and lock-up points), and check the line-up with the engine when the tranny housing is without its innards. The 727 steals more power and is much heavier.


Author:  Fonaf [ Thu Nov 29, 2018 11:25 pm ]
Post subject:  Re: I know this concept isn't popular, but OD automatic question

Sorry for raising an old topic, but maybe someone will be interested.

I rebuilt one for my truck about 4 months ago using a kit from Pro-Built Automatics

I bought a 93 core that was described as having no overdrive. Opening it up I found some of the nastiest smelling oil and a fractured sun shell. Ultimately, in addition to the kit, I also replaced the reverse/input drum, just in case. The kit includes a new OEM sunshell that is hardened and supposed to address the earlier failures. You'll hear conflicting opinions on that one.

Overall it wasn't too bad, but I did have to make a handful of tools. You'll need a spring compressor for the forward clutch pack down in the very bottom of the transmission, but that one is easy to do using a long bolt, a large washer to pull against the transmission case, and a U-shaped piece of steel to contact the spring carrier, but leave the center open so the snap ring can be removed. I ended up taking some scrap 3/4" steel rod, cut a large washer in half, and welded the halves onto either end of the rod so that the cut-ends contacted the spring carrier. The rod had a hole drilled through the center for the bolt to pass through.

Another tool you'll need is a spring compressor for the input drum. I got by using a piece of 3/4" angle iron that I filed to size so that it fit snugly into the snap ring groove. I then drilled and tapped two 1/4-20 holes that lined up with the ring of the spring carrier. I was able to walk the bolts down to compress the springs enough to remove the snap ring. However, the snap ring was a bear to remove and still required some finesse. When I put it back together, I had much stiffer springs to install (part of the shift kit)... let's just say I kept my face clear of that assembly.

The only other tools you'll need are bushing drivers. The bushings can be driven out using a chisel point punch which will destroy them, but you'll need a proper driver to drive them in. Care must be taken as some of these are very soft and easy to damage. I ended up taking some 2.5" round aluminum bar stock and machined it as needed for each set of bushings. Fortunately I've got a small table-top lathe that could do the job. I certainly wouldn't try to do this with some sockets.

Otherwise, as Durallymax said, it's all about patience and keeping your work clean. You should count on having to order different thickness steels to get some of the clutch packs shimmed correctly, fortunately I got lucky. I do have one pack that is .010" looser than what Pro-built advised in their instructions, but it was well within factory spec and I'm not drag racing or making shifts with the torque management disabled.

I also replaced the torque converter with a new unit, I didn't want to risk debris from the old one killing my work. I replaced all of the solenoids, except the pressure control solenoid. The pressure control solenoid was supposed to be pretty reliable (and pricey), but I got unlucky and had to drop the pan to change it for a new one. Lesson learned: Do it right the first time! This is no different than an engine... don't cut corners unless you're ready to do it all over again. I would have rather spent that $100 up front rather than spend time checking transmission pressures and dropping the pan. I also risked burning up the 3-4 clutch because the line pressure was too low. I got lucky!

All said and done, I wrapped up about $1200 in my complete 4l60e rebuild kit like this , bellhousing to tailshaft. Bear in mind that in my application the engine makes about 400 ft-lbs so I felt it was too risky to get away with a stock rebuild, hence the added cost of the Pro-built kit. If I needed a rebuilt transmission for a stock truck, I'd likely let someone else do it for me. In this case, however, I was looking for the challenge and didn't want to pay $2000+ for a comparable unit from a reputable builder.

One intresting video about rebuild

Author:  olafla [ Sun Dec 30, 2018 3:59 am ]
Post subject:  Re: I know this concept isn't popular, but OD automatic question

Great video, Fonaf! :D


Page 1 of 1 All times are UTC-07:00
Powered by phpBB® Forum Software © phpBB Limited