LSX/4L60e - Convertor wont match up

[pjku79]

OK, I am not sure if this is an issue with mixing and matching parts or what, but I have two convertors and neither of them seem to work with my engine (5.3L gen III - 99 silverado) and trans (4L60E, supposibly out of a Capri Police car) combo.



The first convertor is a TCI 2600 that I bought which was suppose to work for a LS1/4L60e. I assumed that would work fine for my application. I tried installing this one first because I was planning on using it. What I realized is the nose part that went into the transmission seemed to be too long. It was longer than the stock one I have whic is out of the supposed Capri. It seemed to be bottoming out on the transmission. This cause there to be about a 0.25" gap between the engine and trans once the TC was flush with the flywheel.

The second convertor from a Capri seemed to be fine on the trans side, but when it mated up with the engine it was flush on the flywheel, but the circular piece that is suppose to go into the center of the flywheel was too short. I might be able to get this one to work, but I was concerned that is wouldn't be perfectly centered (mainly because the holes on my flywheel is bored slightly because the previous owner had it mated with a TH400).

I am hoping someone is going to be able to take a look at the pics or maybe its obvious what I am doing wrong. As always this is urgent, because my friend needs his engine hoist back on Friday. Thanks for the help.

[greg5436]

The large converter looks like it is out of a allison 1000 diesel.The smaller one is correct for the trans in the pics. The engine you have is a later model than the trans.that engine probably had a 4l65 or a 4l80e behind it, so the flywheel would be different. That is why your converter to flywheel spacing is wrong.look into a different flywheel first. Greg

[greg5436]

I was wrong on the large converter,not an Allison because of the converter hub.but is way to big for that trans. Greg

[pjku79]

Oh yea, duh. I guess I never even looked at the flywheel. It does say 08 on it. I guess I need to find one for a gen III motor. Thanks

[pjku79]

OK, I am still fumbling with this. I bought a new fly wheel. They were basically the same. Any idea? I am looking for a stock silverado TC but haven't located one cheap locally yet.

[tooblue]

First question is what year is that Trans..? Not all 4l60e's are the same.

[pjku79]

Is there a data base I can search the part number? I do not really know I was just told it was out of a caprice. It says 5BWD on the sticker which comes up at 95 Caprice when I google.

[Z06vet]

That does not look like its an LSx trans. It looks like the pre-LSx trans that mated to Gen1/2 small block. The LS style does not have that smoothed machine end on the shaft.

[pjku79]

I thought I read some where that the caprice trans was preferable because the trans mount mates up close to the stock position. Are you saying this trans wont work?

[Steve Chryssos]

There's nothing inherently wrong with early 1 piece case 4L60E transmissions. And that's what you have. The trans will bolt up fine. I can build you a hybrid converter that will work. Not like a Prius hybrid. An early style 4L60E spline on the trans side and a LS style front cover with the right depth to make it all work together. And it's engineered to our MuscleDrive™ spec for pro-touring cars, not OE, street/strip or unknown. It's not cheap, but its custom engineered for your car and a critical aspect of your powertrain. With the wrong converter, you'll HATE driving your pro-touring car.

There IS an early trans to LS adapter kit (link below). But you'll still need to have your ducks in a row regarding flexplate, and converter. I feel for you. Mixing and matching these parts is a pain.

http://www.ebay.com/itm/700R4-Early-...-/360332821499

[MarkB]

You have a 300mm billet 4L60E billet converter, this is for LS based removeable bell style 4L60E transmissions only. As Steve mentioned no problem bolting the early style '93-'97 style transmission to your engine, you just will only have 5 bolts holding it on, as the early 4L60E does not have a top bolt hole and the LS engine you have does not have a an upper passenger side bolt hole due to being located in a water jacket. But you do need a special flywheel kit with hub adapter or do as Steve has recommended and get a custom converter that is set for your 30 spline early 4L60E with an LS pilot. Either way works. If you are wanting to use the old converter you have then you can just purchase the flywheel package. If you are wanting a new converter then you might as well order it the way that you need it. Bowler's or Twist can help you out either way.
I hope this helps you out. Feel free to give us an e-mail if you need more specifics or want a quote.

Thanks,
Mark

[pjku79]

How much does one of these custom converters cost? I am not exactly flush with cash right now and was hoping to get the car back on the road soon.

Does the adapter allow me to use the LS TC or the early style TC? I might go that route if I can use the TCI convertor which I purchased for this application.

If not I see two options, purchase the custom convertor and sell the TCI convertor or sell the trans and get the correct truck trans.

[camrat68]

I thought I read some where that the caprice trans was preferable because the trans mount mates up close to the stock position. Are you saying this trans wont work?

I thought that only applied to using the 700R4's behind the 5.7l L05's to replace TH400's out of the late 80's squads?

If that 4L60e is bone stock out of a squad, you'll be replacing it sooner rather than later. I've got three blown ones sitting in my garage awaiting rebuild. All of them were raced behind modded LT-1's. If you decide to move to the truck 4L60 there would probably be some interest on the Impala SS Forum in your old trans. That forum has quite a few members in Texas.
Jim

[pjku79]

Thanks. I'll be sure and post it there. I was told it only had 35000 miles on it.

[MarkB]

The adapter will allow you to use the original early 4L60E converter behind the LS engine. A custom converter is $850.00 + Shipping. Keep in mind that a stock 4L60E from factory with no miles on it was only built for 375 ft lbs, so it is not advisable to put a used transmission in anything that you are going to actually drive hard. The stock 4L60E does not like high RPM either. So you will more than likely be upgrading soon to either a built 4L60E or move to a 4L80E. Hate to give you bad news, but it is just a fact. Buy many have been very lucky... best of luck to you on your project.

Thanks,
Mark