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Quickstop [UK]
Combating adversyty.
Installing a 4L80E in your Typhoon or Syclone is potentially one of the best modifications you can do in terms of reliability and durability. Hot Rod Magazine 2009
4L80Es can handle approximately 500-600 hp (at the flywheel) and 500ftlbs of torque as they are, without any requirement for expensive internal upgrades. You can however upgrade them even to the point of having 6 gears but it is, as always, a question of money. I have a 4L80E and after reading about the failures of 700R4s I decided I never wanted to go down the never-ending repair route. That said, many people run 700R4s and have had good experiences; each to their own.
PROS:
Never rebuild or replace your transmission again* (for 99% of us)
More power handling capability
Transbrake possible
CONS
Expense – budget around $5000 for one.
$500 core charge
$900-1100 new Torque Converter
$1200 install kit miscellaneous items (not all listed here. Speak to a vendor about the stuff for the internals. This was the approx price I paid George Blake to provide me with parts before he left the community. A great loss for us and our transmissions but the other vendors have started selling parts and hopefully some members will step up too.)
$300 – install SyTy output shaft into trans
$850 – trans computer (you can use a stock GM ECM but it needs re-wiring etc)
$100 – shorten drive shaft
$100 – DEXRON III ATF
Obtaining parts for the syty is tricky but not impossible. The following vendors support SyTy 4L80E conversions:
RPM
Waller Performance
STOUT74 (member, not a vendor per se)
RenzFab
MYTHS
1. People think it is way heavier than a 700R4. This is not totally true. 700r4 vs 4l80e The difference is 40 lbs. Eat less for lunch, hit the gym and have salad once in a while
2. It takes more power to drive and will eat your gas mileage – again, not conclusive. Smoother gear changes and custom throttle settings more than mitigate this even if it were true.
SKILLS REQUIRED
You need to have some time and confidence in wiring and tuning the trans. It isn’t actually that hard to do and will really advance your knowledge of the truck.
This was my first tranny install – like I said, I plan to never do it again and figured why not start where I meant to end up?
There are other expenses that I may have missed but that’s a good ballpark estimate. It can be higher or lower depending on what you choose.
Installing the 4L80E is not a massively difficult undertaking assuming you have the right equipment:
Transmission jack
Tall axle stands if possible
Grinder (optional – I’ll elaborate later)
Sockets and usual tools
Threadlocker
Flexplate tool for turning the engine (can’t stress enough how useful this was)
You will also need the following components for the install:
- 4L80E to stock syty transfer case adaptor plate
- cross member trans support
- trans mount (solid eng mounts = poly trans mount and vice versa)
- gear selector bracket (optional but clearances are tight and hammering the stock one is tedious (they’re only $20)
- Trans control computer (see below)
- Trans shifter cable (HD one preferably)
- New prop shaft – Gilbert or equivailent
- 4L80E torque converter – many options available
- 15 litres of DEXRON III Automatic Transmission Fluid.
DO NOT USE SYNTHETIC ATF
- Transmission lines
- *fuel lines* (the stock syty lines were attached to the trans – once the trans is shifted back by the 3.25”, they don’t work. Leave them in and you risk false knock being picked up). Some people use them though.
Preparatory Work
You need to get your stock driveshaft shortened by 3.25” as the trans itself is 3.25” longer. The prop shaft is correspondingly longer:
Remember the grinder? Well, you CAN cut out your rear cross member where the transfer case rests but why would you want to hack in to your truck if you don’t need to?
If the engine is out then you can manoeuvre the entire trans and t-case assembly over the cross member. A lot of people will choose to remove it or notch it. I had the engine out so it was a no-brainer.
The trans tunnel has a lip at the front of the vehicle which can impede installation. Get rid of this if you can. Hammer it or cut it away so you have no trouble reaching the bolts that connect the block to the bell housing.
Installation:
THIS ASSUMES THE ENGINE IS OUT OF THE TRUCK.
Thread the computer harness through a hole in the truck. This depends on where you want to mount your computer but it seems pretty easy to choose somewhere. I hid mine under the centre console under the gear lever right next to the grommet where the shifter cable goes.
This was a similar installation:
Or:
Cut the grommet with some snips and then thread the wiring harness through and down under the truck. There should be three cables:
VSS
TOSS
Main harness connector
We’ll come back to these. Keep them out the way for the time being.
Get the trans under the truck in a position where you can mate it up to the engine. Ratchet straps and a friend and a couple of jacks are one way of doing it. A lift would be better. It is heavy – be careful.
You now need to get the rear cross member installed. On the driver’s side of the truck, the brace goes OVER the frame
and on the passenger’s side of the truck the brace lines up with the obvious holes.
Use the brace to support the trans but don’t tighten the trans mounts just yet as you still need to mate the trans to the engine.
At this point you need to connect the torque converter onto the output shaft of the trans.
You can do it before hand but it’s heavier and if you have a cross brace to hold it in, it might get in the way. Use your own judgment.
Your TC will take about 2 litres of ATF fluid. The best way I found to get it to fill the TC was to fill it to the neck then rotate the TC. This will take a few minutes but you need to do it.
Then you need to angle the TC and slide it onto the snout of the trans. The TC needs to slide all the way down so that the face of the TC is at least 5/8” away from the edge of the bell housing.
The flexplate sticks out a fair way...
The TC stuck on mine at 1/2" but then after some jiggery pokery it went in all the way. It is keyed so try and line them up.
What you are looking to do is push the TC down so that when you connect the bellhousing to the engine, you have to pull the TC FORWARD to connect it to the flexpplate.
IF YOU TRY AND FORCE THE TC ON THE SNOUT THEN YOU WILL CRUSH THE PUMP AND WILL NEED A NEW TC AND POSSIBLY A TRANS REBUILD/ FLUSH.
People have apparently done this.
It isn’t too bad to get the TC on, just some wiggling to get the keys on the snout of the trans to align inside the TC. Took me 5 minutes but can vary depending on luck. Putting the trans in park (all the way forward on the selector lever) will help as it is one less rotating assembly.
4L80Es can handle approximately 500-600 hp (at the flywheel) and 500ftlbs of torque as they are, without any requirement for expensive internal upgrades. You can however upgrade them even to the point of having 6 gears but it is, as always, a question of money. I have a 4L80E and after reading about the failures of 700R4s I decided I never wanted to go down the never-ending repair route. That said, many people run 700R4s and have had good experiences; each to their own.
PROS:
Never rebuild or replace your transmission again* (for 99% of us)
More power handling capability
Transbrake possible
CONS
Expense – budget around $5000 for one.
$500 core charge
$900-1100 new Torque Converter
$1200 install kit miscellaneous items (not all listed here. Speak to a vendor about the stuff for the internals. This was the approx price I paid George Blake to provide me with parts before he left the community. A great loss for us and our transmissions but the other vendors have started selling parts and hopefully some members will step up too.)
$300 – install SyTy output shaft into trans
$850 – trans computer (you can use a stock GM ECM but it needs re-wiring etc)
$100 – shorten drive shaft
$100 – DEXRON III ATF
Obtaining parts for the syty is tricky but not impossible. The following vendors support SyTy 4L80E conversions:
RPM
Waller Performance
STOUT74 (member, not a vendor per se)
RenzFab
MYTHS
1. People think it is way heavier than a 700R4. This is not totally true. 700r4 vs 4l80e The difference is 40 lbs. Eat less for lunch, hit the gym and have salad once in a while
2. It takes more power to drive and will eat your gas mileage – again, not conclusive. Smoother gear changes and custom throttle settings more than mitigate this even if it were true.
SKILLS REQUIRED
You need to have some time and confidence in wiring and tuning the trans. It isn’t actually that hard to do and will really advance your knowledge of the truck.
This was my first tranny install – like I said, I plan to never do it again and figured why not start where I meant to end up?
There are other expenses that I may have missed but that’s a good ballpark estimate. It can be higher or lower depending on what you choose.
Installing the 4L80E is not a massively difficult undertaking assuming you have the right equipment:
Transmission jack
Tall axle stands if possible
Grinder (optional – I’ll elaborate later)
Sockets and usual tools
Threadlocker
Flexplate tool for turning the engine (can’t stress enough how useful this was)
You will also need the following components for the install:
- 4L80E to stock syty transfer case adaptor plate
- cross member trans support
- trans mount (solid eng mounts = poly trans mount and vice versa)
- gear selector bracket (optional but clearances are tight and hammering the stock one is tedious (they’re only $20)
- Trans control computer (see below)
- Trans shifter cable (HD one preferably)
- New prop shaft – Gilbert or equivailent
- 4L80E torque converter – many options available
- 15 litres of DEXRON III Automatic Transmission Fluid.
DO NOT USE SYNTHETIC ATF
- Transmission lines
- *fuel lines* (the stock syty lines were attached to the trans – once the trans is shifted back by the 3.25”, they don’t work. Leave them in and you risk false knock being picked up). Some people use them though.
Preparatory Work
You need to get your stock driveshaft shortened by 3.25” as the trans itself is 3.25” longer. The prop shaft is correspondingly longer:
Remember the grinder? Well, you CAN cut out your rear cross member where the transfer case rests but why would you want to hack in to your truck if you don’t need to?
If the engine is out then you can manoeuvre the entire trans and t-case assembly over the cross member. A lot of people will choose to remove it or notch it. I had the engine out so it was a no-brainer.
The trans tunnel has a lip at the front of the vehicle which can impede installation. Get rid of this if you can. Hammer it or cut it away so you have no trouble reaching the bolts that connect the block to the bell housing.
Installation:
THIS ASSUMES THE ENGINE IS OUT OF THE TRUCK.
Thread the computer harness through a hole in the truck. This depends on where you want to mount your computer but it seems pretty easy to choose somewhere. I hid mine under the centre console under the gear lever right next to the grommet where the shifter cable goes.
This was a similar installation:
Or:
Cut the grommet with some snips and then thread the wiring harness through and down under the truck. There should be three cables:
VSS
TOSS
Main harness connector
We’ll come back to these. Keep them out the way for the time being.
Get the trans under the truck in a position where you can mate it up to the engine. Ratchet straps and a friend and a couple of jacks are one way of doing it. A lift would be better. It is heavy – be careful.
You now need to get the rear cross member installed. On the driver’s side of the truck, the brace goes OVER the frame
and on the passenger’s side of the truck the brace lines up with the obvious holes.
Use the brace to support the trans but don’t tighten the trans mounts just yet as you still need to mate the trans to the engine.
At this point you need to connect the torque converter onto the output shaft of the trans.
You can do it before hand but it’s heavier and if you have a cross brace to hold it in, it might get in the way. Use your own judgment.
Your TC will take about 2 litres of ATF fluid. The best way I found to get it to fill the TC was to fill it to the neck then rotate the TC. This will take a few minutes but you need to do it.
Then you need to angle the TC and slide it onto the snout of the trans. The TC needs to slide all the way down so that the face of the TC is at least 5/8” away from the edge of the bell housing.
The flexplate sticks out a fair way...
The TC stuck on mine at 1/2" but then after some jiggery pokery it went in all the way. It is keyed so try and line them up.
What you are looking to do is push the TC down so that when you connect the bellhousing to the engine, you have to pull the TC FORWARD to connect it to the flexpplate.
IF YOU TRY AND FORCE THE TC ON THE SNOUT THEN YOU WILL CRUSH THE PUMP AND WILL NEED A NEW TC AND POSSIBLY A TRANS REBUILD/ FLUSH.
People have apparently done this.
It isn’t too bad to get the TC on, just some wiggling to get the keys on the snout of the trans to align inside the TC. Took me 5 minutes but can vary depending on luck. Putting the trans in park (all the way forward on the selector lever) will help as it is one less rotating assembly.
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