Question about 4L80E [Archive]

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TheMonkey

12-09-2006, 04:15 PM

I purchased a working 4L80E that came out of a 1 ton crew cab 6.2L diesel pickup. It was rebuilt since new.

Going into a '61 Pontiac. The Pontiac is getting designed with a cam for low end torque. I have not decided on rear gears or stall speed yet, although I am inclined to have a very tight converter.

Then, I started thinking that I might be okay with the converter that is in there, particularly as the price of a new TC is nearly a grand. I'll be about 525hp, & 600#lb torque, so a stock 4L80E should not need to be built up. Would be nice to just drop this one in as is.

Question is, would a stock converter have lockup & what kind of stall speed? How can I tell?

Thx, Scott.

myclone

12-09-2006, 04:38 PM

Scott,

I cant quote the exact stall numbers but be aware that a diesel converter is going to be a really really low stall and tight compared to a gas converter.

The stocker has a lock up clutch and you would probably be able to use a stock converter with the ponchos low RPM tq but I think you would be happier with an aftermarket piece. If cost is an issue then by all means give it a try and see how you like it but be aware that the stock 80E coverter is one heavy SOB...like 65lbs heavy. Thats a lot of rotating mass to accelerate so goig with an aftermarket piece would free up some power just from the parasitic drag/weight loss.

Dave

TheMonkey

12-09-2006, 05:28 PM

Dave- Thanks for the reply.

Sounds like this is not a good place to try and save $$. I can't believe the size of the stock TC. I think the weight difference is about 25#, and I had not thought about the fact that it would be rotating mass, making the weight benefit exponential.

I just found this CC article about a swap from stock TC to aftermarket in the 4L80E. http://www.carcraft.com/howto/1031/index9.html

Any suggestions on where to go for a TC? Also, considering my expected power, should I consider any other upgrades while the tranny is out? Is a shift kit something that would be worthwhile? Can a non tranny guy put in a shift kit? This is a street project that might see a few trips down the strip, but mostly for cruising.

myclone

12-09-2006, 07:30 PM

Scott,

Ive never used a Pro Torque piece myself but some fellow trans guys have and if memory serves me correct they seem to be happy with them. I personally use Coan coverters since Im beating the trans pretty hard but be aware they can be spendy unless you have buds/connections will sell them to you for the "good ol boy" price. I paid $1k for my Coan tc and that was through a bud who has an on line speed shop so even having "connections" doesnt make it a cheap purchase. I have seen some unhappy people who bought TCI and/or B&M converters...granted they didnt pay a huge amount for them but for me if something doesnt work it doesnt matter if its cheap.

As other folks will attest that the 80e is a pretty tough piece right from the factory and builds making ~1k ftlbs using an 80e are out there. Its not cheap to do a max build on an 80e but 99% of the ppl out there dont really need a max effort build (IMO) with this trans either. I guess what Im saying is that if you start with a running unit that doesnt have a zillion miles on it you can prolly stab it in the car and have fun with it. If it has high miles but is a functional unit then normally all they need is freshening (new clutches/steels, seals, etc) with no high $$$ parts needed...unless you want to put them in.

As for shift kits I use the Transgo HD-2 kits in the 80Es Ive built due to the Transgo kit installation fixing the possibility of run away line pressure that can happen with a stock trans (~500psi=cracked case=bad). Is a shift kit mandatory? Not really but IMO the stock 80e accumulator springs can be a little on the soft side...but like I said thats my opinion and we all know they are like belly buttons LOL. The Transgo kits arent the most simple kit to put in but once you do a couple they arent that bad (the instructions that come in the kit are horrible and hard to follow) and a hard core weekend wrench could handle one. If youre comfortable with building EFI engines from just a bunch of parts to a running engine then the shift kit is a couple hour job but if youre a "bolt on" only type gear head (no offense if you are) I highly suggest that you drop the trans and shift kit off at a reputable shop and let them install it. Its not rocket science by any means but nothing is more frustrating to a weekend wrench than wrestling a 200+ lbs trans in and out of a vehicle a few times if the shift kit isnt installed correctly...or worse that heavy high $$ trans gets damaged.

Hope that helped you some.

Dave

TheMonkey

12-10-2006, 07:50 AM

....

Hope that helped you some.

Dave

For sure, thanks.

Another question: if I want to clean up the tranny, and maybe paint it, what's the best way about this? Can I safely clean it with a pressure steam cleaner? Would regular engine bay degreaser work okay or is there a risk to getting water/degreaser into seals?

Thanks, Scott.

myclone

12-10-2006, 04:53 PM

For sure, thanks.

Another question: if I want to clean up the tranny, and maybe paint it, what's the best way about this? Can I safely clean it with a pressure steam cleaner? Would regular engine bay degreaser work okay or is there a risk to getting water/degreaser into seals?

Thanks, Scott.

Scott,

I clean my rebuilds up with brake cleaner rather than a pressure washer. Ive found that with high pressure water/soap I end up wearing most of it once you start directing the spray into the little nooks and crannys where crud accumulates not to mention its tough to seal the openings up well enough to keep ~3000psi water out. The best way Ive found to REALLY clean a trans case is to use 6 or 8 big cans of brake cleaner along with a stiff brush and some elbow grease. Its a smelly job but the cases come out squeaky clean and ready for primer/paint.

I seal up the coolant line fittings with some duct tape as well as seal up the front pump where the torque converter slides in and and the tail shaft opening. Brake cleaner cuts the crud easily and doesnt hurt the electrical plug and it does attack the glue on the duct tape but being careful not to drench the locations where the tape is keeps anything from getting inside.

FWIW I built the below fixture out some pieces from the scrap metal pile and a el cheapo harbor freight engine stand which makes working on as well as cleaning a trans a tremendous amount easier. Its not pretty but I whipped it up in about an hour just eye balling the measurements and it beats the heck out of wrestling a ~200lb trans around to position it for work or cleaning. Something similar would probably save you some gray hair and busted knuckles.

TheMonkey

12-10-2006, 06:53 PM

I'm not sure why they call it 'brake cleaner'. It seems to work great on everything! Great tip on the tranny mount to get into an engine stand. I had not thought of that, and this tranny is a bear.

I'm not real familiar with the history of this tranny. Just what the guy told me who I bought it from, and I have to take is word at face value. Now that I have it on a pallet, is there some kind of checkup procedure that a tranny shop could do to test it? Maybe a tranny dyno or something? What should I ask the shop to perform, and is it possible for them to test it without getting to deep into it?

myclone

12-10-2006, 07:13 PM

I'm not real familiar with the history of this tranny. Just what the guy told me who I bought it from, and I have to take is word at face value. Now that I have it on a pallet, is there some kind of checkup procedure that a tranny shop could do to test it? Maybe a tranny dyno or something? What should I ask the shop to perform, and is it possible for them to test it without getting to deep into it?

While not as common as hair on your head there are well equipped trans shops out there that have trans dyno's that can test a unit out of the car. Basically its an elelctric motor that takes the place of the internal combustion engine thats hooked to the torque converter and a power asorbstion unit of some type is attached the output shaft. The trans is then tested for proper pressures, shift quality, shift timing, slippage, etc...everything youd check for if the trans was installed in a vehicle.

The chances of finding such a dyno are better if you live in or around a larger city but the further you get out in the boonies the more scarce they are. I live in a fairly small town and the closest trans dyno I know of is ~4hrs away but you may have one closer to you...asking a reputable shop if they know of one close by would be my first step if you want to have it dynamic tested.

I have no clue what it costs to dyno test a trans as Ive never had it done but I would guess that it would be some what cheap ($150 maybe?) since it should only take about an hour to get the trans hooked up on the dyno and test it.

There is other equipment out there that can pressure test the trans and actuate the electricals but they dont test the dynamic performance of the trans. Basically the machine just tests for leaks internally but no shift quality or rotating parts tests are performed. I would guess this test may be a little more expensive since the units Ive seen require the valve body to be removed and the test equipment valve body installed in its place. Not a hard job but it does take more time than just bolting the trans to a dyno (time=$$).

To be honest its tough to tell the health of a trans without tearing into it to look at the wear parts. The fluid color and smell will tell you a BUNCH but to go much further you have to tear the trans apart (read: labor/$$). If you pull the pan off and only find a little gray slimey junk in the very bottom of the pan that is generally a sign of a used but healthy unit. If you find any chunks of metal bigger than a grain of pepper that you cant crush with your finger nail there may be something internal that needs attention. If the fluid is red or even slightly red/brown and the pan contains no debri of any significant size that will stick to a magnet youre prolly in good shape. The slimey gray funk in the bottom of the pan is normal too from what Ive seen in the 80E in my dually as well as my Syclone. If the fluid is black or really REALLY dark as well as having a nasty burnt smell then your trans may be in need of a tear down/rebuild or if you find any significant metal chunks then I would highly recommend a tear down and inspection.

Just remember that a trans shop is in business to sell you a rebuild and/or parts so unless you have a shop that you know and who does work for you I would HIGHLY recommend at least pulling the pan and taking a look for yourself. At the very least pull the pan and take a look before you take the trans to a shop so that you are an informed customer who hopefully wont have to shell out $$$ for a rebuild you didnt need in the first place.

As for what to tell the trans shop to do thats a toughy....thats kind of like telling a high end chef how you want your steak cooked then trying to show him how to go about it. Most established trans shops have qualified ppl who know what to do and how to go about it. The only advice I can give you is that the ppl in the trans industry I rub elbows with arent too fond of the chain store type trans shops (aamco for one) so try to find an independant shop that does performance based builds. Least thats my opinion and as I mentioned before opinions are like belly buttons LOL.

HTH

TheMonkey

12-11-2006, 08:59 AM

myclone

12-11-2006, 10:46 AM

Dave-

I think I'm going to get this thing on a stand and drop the pan to look for any shavings or trouble. The oil on the stick looks red and doesn't smell burned. I called the trans shop that did the rebuild and has their sticker on it. He said based on their serial number on their sticker, it has been about 5 years since rebuild. So without any metal shavings, I'll prob attempt the shift kit to make sure everything is fresh.

If the fluid is good then chances are that the trans is healthy just be aware that new fluid can be bad sign. Lots of times the cheap/last ditch effort at bringing back a malfunctioning unit is to do a filter and fluid change. Used but good fluid usually=good things but brand new unused fluid=a bad omen sometimes.

It seems that Transgo has just one kit (except for their kit with vacuum modulator for manual shifts); is the following link the one that you used? http://store.summitracing.com/partdetail.asp?autofilter=1&part=TRG%2D4L80E&N=700+115&autoview=sku

TransGo actually makes two different kits but the one in the link above appears to be an HD2 that I use going by the pic. FWIW you can pick the same kit up at the following link for a little more than half the price summit wants (scroll down a little to the HD2 kit).
http://www.transmissionpartsusa.com/Transgo_shift_kits_s/136.htm

FWIW there should be a list of parts on this site that Ive posted previously in a thread about the 80E that may be worth looking at. Theres a couple small pieces that will make life easier on you like a short shift rod (the stock one sticks out of the side of the trans ~3"..possible exh/floor pan interference) and the rear trans lube coolant line fitting adaptor kit if the trans you have is a 97 or newer. You should be able to do a search for user name "myclone" and key word "80E" and find the parts list I put togeather for the 80E (seems I posted the list in a 3 or 4 page thread IIRC).

FWIW II:
I cant stress this enough and you'll soon see what Im talking about if you do the shift kit yourself but read through the instructions a few times and tripple check each step before drilling holes or plugging ports in the seperator plate. The Transgo kit instructions are detailed but most ppl will find them tough to follow. I dont know how to explain it other than they seem to be written by someone who was writing down the info off the top of their head. As in the instructions dont seem to follow a point A to point B style they just bounce around and youll find yourself revisiting a part you worked on previously at different points in the instructions. It would seem (at least to me) that if one was to do some work on say part X that the instructions would be written in such a way that every mod needed to part X would be done at one time then you move on to part Y. Not so with the Transgo instructions....you work on part X for a while then move on to part Y then a few steps later youre back working on part X again. Maybe its just me but I find that a little confusing and hard to follow for the first go round or so. Take your time and tripple check each step and you should be fine....at the very least if the instructions frustrate you walk away, have a cold one, and then come back to it later (I had to do that on my first one....a couple of times LOL).

Lets us know how things turn out and if you have questions feel free to ask and I'll do what I can to help.

Dave

Karch

07-19-2007, 10:59 PM

Scott, and updates?

Dave, how hard are these to rebuild?

I like the idea of the trans dyno to check it all out, but first I need to get one, then tear into it.

Engines don't bother me...they're easy enough, but these things-I've never built one.

Thanks.

Steve Chryssos

07-20-2007, 02:42 AM

Dave is no longer with us. He passed away in an accident. I wish he was still here--had a ton of good info. Click on his handle and read some of his posts. Very informative and detailed. RIP Myclone!!

TheMonkey

07-20-2007, 05:15 AM

This was the first I heard what happened to Dave. It really made me pause. I'm really sad about this. This thread is an excellent example of how helpful he was. I just now read through the February post about what happened, and it will change my shop safety regime.

Dave - My prayers are with your family.

Karch- I'll send you a PM on status, I'll leave this thread as-is.

Karch

07-20-2007, 07:50 AM

I am sorry to hear this.

All the best to his family and friends.

Steve, thanks again.