Sep 12, 2012 // BPU+ //
Cam Gear Install
What you do to
your car following this article is your responsibility. Don't come to me if you ruin
something while attempting this install.
It has been dyno proven that using adjustable cam
gears can yield us ~10rwhp. I only installed the exhaust cam gear because
that's where most of the HP gains will be obtained from. Some say the intake side
isn't worth doing, (most do it to look pretty) and the gains are very minimal. The
timing belt is covered all the time so I didn't feeling like shelling the extra dough for
Objective: This technical article will provide the installer
with the proper information and procedures to install a single or a pair of adjustable cam
gears on their twin (or single) turbo Supra.
Socket set, socket
extensions, 10mm, 15mm, 22mm box end wrench, electric screwdriver with extension for 10mm
socket, 5mm (I think) allen wrench, wood blocks for the rear tires, jack and jack
stands, a bucket, some shop rags, pliers, flat tip screwdriver, loctite (I used 271), and
possibly some other tools I didn't list.
Time: From start to finish, a good
solid 2 1/2 hours. Second time around…maybe 1 1/2 hours TOPS. 🙂
Let's start this badboy! Before you actually start, I
suggest you read this article at least 10 times to understand what you're going to be
doing. (Or until you can do each procedure while half-ass asleep. 🙂
1. Disconnect the battery cables and remove the battery, set aside. Remove the
battery clamp, set aside. Using a 10mm box end wrench, remove the 3 10mm bolts
holding the battery tray down. Set battery clamp and 3 10mm bolts in tray, set aside
next to battery. Make sure it's up against the wall so someone doesn't trip over it.
2. If applicable, disconnect the center piece of your strut
brace, set aside so it won't get scratched and damaged…the best spot would be the hatch.
3. Remove the 10 allen head bolts on the spark plug cover,
so it won't get scratched and damaged, once again, the hatch is a safe place. Take a
small baggie and place the 10 bolts inside and place on your bench or in the hatch.
All the stuff placed in the hatch won't be touched until reassembly. Since
that spot is choice location, it would be very difficult to really lose anything while
attempting this install.
4. Take your pliers and squeeze the clamp on the radiator
hose on the radiator flange. Slide the clamp back a good 5-6 inches. ***Make
sure your engine is COLD or you have waited long enough to bring the coolant temperatures
down!*** Take some rags and place them under the flange to catch most of the coolant
that doesn't make it into the cup. Take your cup and place it under the radiator
hose, pull (wiggle) the radiator hose off and aim it into the cup. You can tip the
hose down allowing coolant to run out into the cup. Do this a few times to get most
of the coolant out. Repeat for the other end of the radiator hose. You will
want to stuff some clean shop rags into the opening to each end to soak up any more
coolant that flows out.
5. This is where you need the jack and jack stands.
Put the wood blocks behind the rear tires to keep your car from rolling away.
Lift up the front end of the car and place jackstands under each allocated location
for jackstands. Place jack aside to prevent a trip hazard. Make sure
everything is secured at this point before crawling under the front of the car.
6. Take your electric screwdriver and use your 10mm socket
and lay under the front end of the car and remove the plastic “Engine Under
Place the bolts
in a baggie and place the screws in a separate baggie, then place both baggies in a single
baggie and stash in the hatch to prevent them from growing legs and walking away.
Removing the plastic cover will do the following: a. Provide access to
the bottom mounts of the radiator, access to the removable harness for the stock electric
fans, and access to the bottom clip of the fan shroud b. provide access to the
timing belt tensioner.
7. You want to remove the harness attached to the fan
shroud. You do this by unbolting the 2 10mm bolts holding the fan shroud to the
radiator. Just place the bolts back into where they came from once you back them out
enough to remove the shroud. Then you go underneath the car and unbolt the 3
10mm bolts holding the bottom of the shroud on. While you're down there, disconnect
the harness/plug going to the temp probe (I think it's a temp probe), disconnect the 2
plugs for the electric fans, and using a flat tip screwdriver, from the top of the shroud,
push in the tabs to the stock zip tie holding the harness to the shroud. For
the 3 10mm bolts, you should just be able to leave them bolted in while removing the
shroud. The part where the shroud attaches is open and the bolt “clamps”
the shroud bottom down. Unclip the bottom half of the shroud, it's pretty straight
forward and should be obvious, remove the 2 clips and swing out the bottom half.
Remove the fan shroud and set aside.
8. Take your allen wrench
(5mm) and remove the
timing belt cover. There are 3 bolts holding it on(STEP #5 in the next
scan). Take the 3 bolts and place them in a baggie and put
Upper radiator hose and timing belt cover.
9. See here, under STEP
#6, LOOSEN and DO NOT remove the drive belt tensioner. I think it's a 12mm socket.
10. Look at following diagram before going any further.
7a and 7b. At this point, you want to take note of the little punch marks and paint
on your stock cam gears. They will be pointing at the notches that are indicated
behind the cam gears. You want to take a ruler and a permanent marker and mark on
the belt (make the line above the 'ridge' of the [either cam gear will work, I'm focused
on the exhaust side for this install, but can be applied to both for installing a pair of
cam gears] cam gear) of exact position the stock cam gear was located in.
When the crank is at 0 the cam gears should
each look like this, if the crank is at 0 and the cam gears are not, then turn
the crank another 360 revolution till all match up:
11. Remove the intake plumbing going to the
throttle body, this should give up some free working space. Take a 22mm open end
wrench and a 22mm socket and place the wrench on the crank pulley bolt and place the 22mm
socket on the cam gear bolt. ALWAYS remember to turn clockwise on the crank pulley
bolt. But don't turn the crank pulley here! Use it to keep the cam gear bolt
from moving. Carefully loosen the cam gear bolt, but do not remove, yet.
Take a 12mm socket with extension and go
underneath the car. Look up to the right and you should see the alternator right
above the sway bar. Behind that, locate the timing belt tensioner.
LOOSEN the 2 bolts, but DO NOT
REMOVE them! This should give you enough slack in the timing belt to remove and
reinstall the timing belt over the new cam gear.
13. By now, you should have enough slack to
easily remove the timing belt. BE VERY CAREFUL HERE!!! You don't want to bump
the cam gears or the crank pulley or you could seriously throw your timing off!
Carefully back the cam gear bolt back out and set aside. Note: I think
on pre97's, you need to order a new cam bolt as it has a smaller washer. Mohd told
me about the new bolt and so I ordered just to make sure, I found out that I didn't need
to use the new one, because it was exactly the same as the stock cam gear bolt. (On
my 97TT) No biggie, I used the new one anyway. You will notice behind the bolt
there is a pin that is offset. See tip below.
Tip 1: Try NOT to move the belt position on the
other cam gears teeth. Have a buddy place his/her hand on top to keep the belt from
budging. Take your new cam gear and slide it partially onto the cam flange at an
angle, then take the timing belt and it should slide and fit on the cam gear exactly like
how the stock cam gear was removed and should be in the same exact position the stock gear
was in. It should look something like this if you've made it
this far. See tip 2 below.
Tip 2: Remember the line you drew on the
timing belt to mark the location where the stock cam gear indentation was?…well, with
the cam gear installed exactly in the first Tip, take some touch up paint/white out and
mark on the new cam gear ridge exactly where the line falls on…this can be used for
future reference if the cam gear is ever taken off and reinstalled.
14. At this point, you're halfway through the
install…take a step back and to the side and this is what the front part of the engine
bay should look like this,
15. Take a break at this point…the rest is
reassembly, but you should pay attention to the torque values.
16. Enjoy your break? The next few steps
will be quick as at this point you will probably know exactly what to do. I will
point out some important areas.
17. Install the new cam gear bolt. Place
the 22mm open end wrench back on the crank pulley and use that to keep the belts from
moving and torque the cam gear bolt to 59 ft.lbs..
18. Using a standard allen wrench, loosen the
cam gears adjustable bolts. On exhaust gear, retard -3º, on intake gear,
advance 1º. On AEM cam gears, it's recommend to use Loctite thread locker to
prevent the bolts from loosening. After placing the Loctite, torque them puppies
down! Make sure you don't move your settings or you will lose the performance
benefit of the cam gears! Double check and triple check this.
19. You should go under the car and torque the
timing belt tensioner to 20 ft.lbs., come back up and then tighten the drive belt
tensioner to 15 ft.lbs..
20. Re-Install the timing belt cover.
21. Re-Install the fan shroud, re-install the
bottom half of the shroud with the 2 clips, plug in the harness back into the shroud, plug
the temperature probe plug back in, plug both fan plugs in and tighten down the 3 10mm
bolts…careful, it's plastic remember?!
22.a Re-Install the plastic engine under
22.b Lower the car back onto it's tires.
Remove wooden blocks.
23. Re-Install the upper half of the radiator
fan shroud via the 2 10mm bolts.
24. Re-Install the radiator hose and move the
clamps back over the flanges.
Re-Install the intake plumbing at the
26. Re-Install battery tray, battery and
27. Double check and triple check everything
up to this point. You should be able to fire the car after you install the battery.
Don't put the spark plug cover back on yet, make sure all your tools are out of the
way and everything of kosher.
28. If everything is OK at this point,
reinstall your spark plug cover and your strut brace and be on your way!
Questions? Comments? Email me
Thanks to Nick P. for his pics and his cam tech info off of his
old tech page for the addition to this install.
Source Links: Timing