Lentech AOD Street Terminator Review

Toms-SC

Registered User
A Lentech Street Terminator Review

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After months of research and venturous threads created by me I bit the bullet last month and bought a Lentech Street Terminator AOD to use on my 1991 SC. I weighed my decision heavily on the feed back the SCCoA generated. Many thanks to David Neibert, Kurt K and SCaddict. In this thread I will attempt to summarize everything Lentech AOD you need to know including juicy tid-bits Lentech fails to mention on their website. I will also include an introduction as to the thought process I went to when I decided to go Lentech. I hope this helps the noobs!

So its time to pick an AOD?
When it is time to pick an AOD you must ask yourself a couple questions:
Is this car a toy?
Is this car a commuter?
What are my HP goals?
Do I want room for expandability?
Can I afford a loss to fuel economy?
And lastly
How deep are my pockets? :p

For the above my car is a street car first, track car second. My horsepower goals is 300HP + to the wheels. I wanted to leave room for expandability so I have the option left open to run some juice if SCaddict keeps pushing my buttons. ;) Seeing how my fuel economy was dismal as it stands already I could afford the loss of a couple MPG. My pockets had to be deep for this and I knew it was going to be expensive.

If you are only concerned with finances of modifying an AOD (IE I have $500 for a new transmission) please follow the following steps:

1) Buy 'For Sale' sign
2) Sell your automatic SC
3) Buy a standard SC

:p

What are my choices?
When it comes down to it you are usually left with 4 choices. I will attempt to weigh them off of each other.

1) Lentech: There is a lot of positive feedback about Lentech through out the internet. I checked the SCCoA and Mustang forums and all Lentech owners seemed to be pleased. Lentech has a nifty electronic over drive delete feature which I know will help when it comes to dyno tuning. The big sell point was the fact you can do the manual 1-2-3 shifting and able to hold reach gear. The downside is the price point. You have to pay to play, big time.

2) Art Carr: Junk. Bad feedback. Although the price point was lower I did not want to risk getting this thing to Canada and it not working. I've yet to read about a happy/working Art Carr transmission on the SCCoA.

3) Local Guy: Hit and miss. I would suggest finding a person through your local area car forums and personal recommendations. If you have somebody you really trust the local guy will have more flexibility when assembling your AOD. I spent an hour with a local transmission guy selecting how my AOD would be built. You can see how it progressed in this thread:
http://www.sccoa.com/forums/showthread.php?t=87452
There was a lot of benefits of choosing the local guy but what turned me away was the quality of components. Having a pretty modified SC I did not want to risk it all to a $100 shift kit. Unfortunately if I substitued in a Lentech Street Terminator valve body my price tag from the local guy would be very close to a true Lentech. I have no doubt in my mind he would have been able to build me a transmission to handle my HP goals but just could not get over the fact of using a $100 shift kit.

4) Ford Re-Man: Ford still offers these. They are perfect for those who don't want to gamble at a 'local guy' and in most cases when installed yourself is cheaper then the 'local guy'. Lets face it, the Ford AOD did what it was suppose to do just fine. I would personally recommend this choice for the 'average' enthusiast who just has some mild bolt ons but required a fresh AOD. Cheap, you maintain the lock up feature and it shifts soft for day to day driving. With my HP dreams the Ford Re-Man was not a good option to go with.

Why did I select the Street Terminator?
Taking everything from the above post it was down between the local guy and Lentech. I picked Lentech for their wizzy valve body. Lentech has two transmissions that will fall into an Super coupe owners scope. The Street Terminator and the Street Bruiser. The Street Bruiser is rated to 400 HP and the Street Terminator is rated to 700 HP. The Street Bruiser has a cost savings of $200 compared to the Street Terminator as it uses a modified 4R70W input shaft and direct drum. I picked the Street Terminator as it was only $200 more for an extra 300 HP 'cushion' which leaves room for big HP. The Street Bruiser would have been fine for my current HP at 240.

The Lentech order process
When I called Lentech I knew exactly what I wanted. I dealt with Len (The owner of Lentech) who was more then happy to empty my wallet to the tune of over +$2700. Len opens up with what car is this going on, what year, what the rear gear ratio is and what the estimated HP/Torque is. Len will then ask you what the car is being used for (street/track) and what size/stall you want the torque converter to be. I selected the street use (this is used to configure the valve body) and a 12" 2000 RPM stall converter. I suspect I will take heat for the large converter but this is a STREET car first and a TRACK car second.

There is a couple available upgrades. You can use a wide ratio gear set and a deep Lentech aluminum transmission pan. There has been mixed reactions to the wide ratio gear set so I decided best to hold out on that and maybe do a gear swap in the pumpkin if I really wanted to. I saw no need for a deep transmission pan either.

Lentech will take half the money up front and call you for the other half before the transmission ships out. I was given a two week build time and a week to ship. I ended up with a four week build time and a 2 day ship time. Sometimes living in Canada has its benefits!

Things they fail to mention on the website. Shipping was roughly $250 by truck freight and a core charge of $100 is added :eek: Free power to weight mod on the wallet.

The Installation
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For a change the shipping company was amazing! The transmission comes bolted into a wooden frame with the converter installed. The converter is mounted by a metal bracket to reduce pressure during shipping. The call before they come and you can arrange to pick it up at their depot. You'll also get a final bill in the mail for your records, a free t-shirt :)rolleyes:), stickers, three tech articles taken from various magazines, installation guide (important) and a warranty card. Also attached to the transmission will be a tag that gives the spacing between the converter and flex plate.

The outside of the transmission has 1 Red 12V wire sticking out for the electronic OD lock out. A config plate has all the necessary information about your transmission. Record the serial number for your records! It may come in handy if your car ever gets stolen or parted.

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You'll have to transfer over some odds and ends from the old transmission so don not chuck it away just yet. I did not do the install but had a good friend do it out of his garage. Remember to blow the old fluid out of the transmission lines. It looks like a can of 'fix a flat' that will attach to your transmission line and blow all of the old fluid out of the system. This will prevent pieces of your old AOD finding its way into your new AOD. The install went really well until he found the spacing between the converter and flex plate was out to lunch! TCI (The people who supply Lentech with most of their parts) did not check the specs of the ~~~~ing converter! :mad: A quick call to Lentech tech support and they recommended adding some washers. He was forced to take it down again and add some $0.30 washers to get it to Lentech's specs. Configure the line pressure to what Lentech says, its in the installation manual that you read. (You did read it, right?). Assuming you don't run into the converter problem the swap is straight forward.

To run the wire we found a screw underneath the e-brake handle that was just there. It did not hold anything in place, it was just there. :confused: We ran the cable up through the screw hole and into my ashtray where my SCT switch lives. You'll have to find a 12V power source and a switch. When activated you'll lock OD out.

Now is a perfect time to cough up $20 and do the rear main seal. It took around 30 minutes to do with the transmission out.

Lentech fails to mention that a transmission cooler is suggested and that higher stall speed converters should have a temp gage. Lentech suggests the operations temperature be around 200C. I am still up in the air about the transmission cooler as this will be plumped through a Griffen rad with a MP fan which is running on high all the time. Furthermore my air dam is still in place. This is to be continued as I have been caught off guard. More research is required.

Initial Running Review
This is based on an hour of City driving. A more long term review will come in a couple weeks time.

It shifts alright. :p Does it ever shift. I told Len during the order process that this was a street car. The shifts are a little too firm for being a street car but this is totally objective. Perhaps it will grow on me? When your on the throttle it will clunk the diff :eek: The best way I can describe it is 'clear and crisp' like a fine beer. The 3rd to OD granny shift is gone. You drive around in OD which maintains the automatic shift feature. The manual shift process is as follows, and you can hold the gears!!! :)

*Lock out OD*
1st Position = 1st Gear
D Position = 2nd Gear
OD Position = 3rd Gear

I can tell you now that I will have to readjust how I drive my Bird. It really makes the car feel different.

Expect a better write up on how it operates as I get a little more seat time. So far I am pleased.
 
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Tom,

Nice write up and preliminary review.

You should also find that under moderate to heavy throttle, the Lentech Street Terminator shifts considerably firmer when shifted manually as opposed to letting the transmission shift it automatically.

David
 
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deep Lentech aluminum transmission pan. ... I saw no need for a deep transmission pan either.

Lentech fails to mention that a transmission cooler is suggested and that higher stall speed converters should have a temp gage. Lentech suggests the operations temperature be around 200C. I am still up in the air about the transmission cooler as this will be plumped through a Griffen rad with a MP fan which is running on high all the time. Furthermore my air dam is still in place. This is to be continued as I have been caught off guard. More research is required.

the deep pan allows more fluid to be added, keeping the overall temps lower. I always thought it was a given, but sadly im seeing that not enough people know about it, that a cooler is not an option when doing a higher stall converter, its a must. IMO when you order a converter, a cooler should be included with it, it is that important. you can check out the cooler i have on my car it will be part number 4739-1 about halfway down on the page linked here. trans cooler there are a bunch of us racer types on tccoa that have this trans cooler. also my trans temps rarely go over 190ish. with very limited driving on it so far.
i have a 4r70w trans that dirtyd0g built installing a Lentech valvebody w/trans brake along with a 4200+ stall converter (its a 4.6L)
 
I have the Street Terminator Valvebody, Calibration 1. All shifts are firmer, though the 2-3 is most noticeable. The TV Cable pressure will also have an impact on the shift into and out of OD. Some guys like to set that a tad high. If you do that it'll be even more abrupt shift. Lentech tweaks that shift so adding the TV pressure isn't really necessary.

You do get use to the shifting. Keeping in mind that the higher pressures used in the shift help protect the transmission clutches helps.

I need to add a transmission cooler to my 90, and it's just a stock AOD with the valvebody. With the stock radiator, fluid temps are gonna run over 200 degrees pretty regularly. A decent transmission cooler is probably a good recommendation for anyone that races with their AOD SC's.
 
Tom,

With a 12" 2000 rpm stall converter, your not going to generate much extra heat. But even on a stock transmission a cooler will extend it's life and there is no such thing as having too much cooling capacity. Did you go with a non locking converter ?

Suggest the B&M # 70264 cooler kit. Can be installed in a few hours and fits nicely on the lower radiator support channel when mounted in front of the AC condensor coil. Also suggest you plumb it in series after the cooler in the radiator. Here's the Summit link.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=BMM-70264&N=700+0&autoview=sku

David
 
what you should do since your shift pattern is different. Get a shifter assembly from a 94+ tbird with the overdrive button. That says 1,2,D and a button for OD just like your AOD works now. I've compared the two shifter assemblys and they are mount the same to the tranny and everything so its a simply swap
 
what you should do since your shift pattern is different. Get a shifter assembly from a 94+ tbird with the overdrive button. That says 1,2,D and a button for OD just like your AOD works now. I've compared the two shifter assemblys and they are mount the same to the tranny and everything so its a simply swap

The only problem with switching to a 94+ shifter is that the OD button is a momentary button and the Lentech VB needs a maintained 12 V source. This can be accomplished with interposing relays, but I haven't done the mods yet. I already have my 94+ shifter :)

Also, when flushing the existing transmission lines, there is a product called transmission cooler flush. It has a hose with a fitting that will connect to the stock transmission lines. It is not available at AutoZone; I've had to by it at better local parts stores. The last can I bought was about $12.
 
David the Lentech Street Terminator I went with is not a locking version so I cannot use a locking converter ($$$).

Lentech suggests a Transmission cooler with '20,000 GVWR'. Any idea what that means?

B&M's current catalog is here, it appears they measure thing in BTU's?

http://www.bmracing.com/media/catalog/9.pdf

Tom,

The 70264 cooler I posted a link to was rated at something like 28,000 GVWR. I used the same cooler on my 91 when I had the same 12" Lentech stock stall non locking converter and the Street terminator VB. I added a 2nd cooler and a fan when I switched to a 9.5" 2700 stall.

That GVWR (gross vechicle weight rating) system refers to how big of a truck the cooler is good for, because it was fairly common to add transmission coolers when a truck was going to be used for towing boats, trailers ect.

David
 
The problem isnt 'GVWR' Dave. The problem is that B&M has decided to show specifications of their current units in that catalog based on BTU and not GVWR.
 
The problem isnt 'GVWR' Dave. The problem is that B&M has decided to show specifications of their current units in that catalog based on BTU and not GVWR.

I understand that. I was just trying to explain to Tom why coolers used to be rated by GVWR and why some companies such as Lentech still use GVWR instead of BTUs when advising their customers on how large of a cooler is needed. Glad to see it shown in BTUs now, because the use of GWVR was a lousy way to quantify the cooler's capacity.

David
 
Well the thing was doing great and I was really enjoying it until something happened and there was a clunking sound that matched the RPM's I was at :rolleyes: I pulled over and gave it two minutes and the sound went away. I was able to drive the thing back with no problem, no sounds and the thing shifting great!
 
When I finally switch over to an auto, I am sure it will be a C4. I dont think I will need OD at the track. I just hope I can find the stuff I need for the swap on the cheap....

Chris
 
Check your driveshaft and the clamps holding it down. Could have had a u-joint come out of position.

I am hoping that this is what the problem is. He dropped the transmission using a new technique by just removing the driveshaft. The pumpkin and the fuel tank were not dropped. I am hoping I can get that sound to come out again so I can pull over and find exactly where it is coming from.
 
I wouldn't wait. Get under there and look around. I need to do the same thing on my car. Thought I had a bad rear diff bushing due to a noise, but I checked the other day and the rear bushing is good as new. I think I got a u-joint going out.
 
I am hoping that this is what the problem is. He dropped the transmission using a new technique by just removing the driveshaft. The pumpkin and the fuel tank were not dropped. I am hoping I can get that sound to come out again so I can pull over and find exactly where it is coming from.

I'm curious, how the heck did he drop the driveshaft without dropping the tank or the differential? That's a trick I need to know.
 
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