Transmissions

General Specifications

T45 Specs:

1^st gear – 3.37

2^nd gear – 1.99

3^rd gear – 1.33

4^th gear – 1

5^th gear – .67

Reverse – 3.22

T45 RPM rate with 4.10 gears at 70 MPH in 5^th gear: 2519 RPMs

T45 RPM rate with 4.30 gears at 70 MPH in 5^th gear: 2642 RPMs

Known Issues/Problems:

The T45 doesn’t suffer from many problems. It does have a slight grind when cold usually and has weak shifter forks (helped with an after market shifter) but there aren’t many synchro problems involved like that of the T3650. Recommended fluid for this is any ATF blend of fluid. 3.5 quarts is needed.

T3650 Specs:

1^st gear – 3.38

2^nd gear – 2

3^rd gear – 1.32

4^th gear – 1

5^th gear – .62

Reverse – 3.28

T3650 RPM rate with 4.10 gears at 70 MPH in 5^th gear: 2331 RPMs

T3650 RPM rate with 4.30 gears at 70 MPH in 5^th gear: 2445 RPMs

Known Issues/Problems:

The T3650 seems to be the most problematic transmission of the SN95 years. It is known to have synchro issues such as grinding even when warmed up. As of 4/22/04, Ford still denies any recall on these transmissions. Recommended fluid for this is GM Synchromesh.. Also, it is recommended to use 3.2 quarts instead of the standard 3.5 quarts as called for in the T45 transmissions. There is now a Ford Service Bulletin that fixes the problems with the T3650.

Cobra T56 Specs:

1^st gear – 2.97

2^nd gear – 2.07

3^rd gear – 1.43

4^th gear - 1

5^th gear - .8

6^th gear - .62

Reverse – 3.38

T56 RPM rate with 4.30 gears at 70 MPH in 6^th gear: 2445 RPMs

T56 RPM rate with 4.56 gears at 70 MPH in 6^th gear: 2592 RPMs

Known Issues/Problems:

The T56 is the strongest Ford released transmission in the SN95 years. So far, the only problem that has occurred is the fact that Ford decided to use a 10 spline input shaft instead of a 26 spline as found in the Viper/GM T56 transmissions. This results in a weaker transmission compared to the other T56s. Any Dextron III fluid will work in this transmission.

4R70W Automatic Transmission Specs:

1^st gear – 2.84

2^nd gear – 1.56

3^rd gear – 1

4^th gear - .7

Reverse – 2.32

4R70W RPM rate with 4.10 gears at 70 MPH in 4^th gear: 2632 RPMs

4R70W RPM rate with 4.30 gears at 70 MPH in 4^th gear: 2760 RPMs

Known Issues/Problems:

I know of no known issues or problems at this time.

* All RPM assumptions are based on if you have a 275/40/17 tire in the rear.

Automatic Transmissions:

Written by MySlow2002GT

Torque Converters:

Torque converters allow the engine to run, while the transmission gears and tires come to a stop. It similar to the same method a clutch works on a manual transmission car. A torque converter is a type of fluid coupling, which allows the engine to spin somewhat independently of the transmission. If the engine is turning slowly, such as when the car is idling at a stoplight, the amount of torque passed through the torque converter is very small, so keeping the car still requires only a light pressure on the brake pedal.

However, if you were to step on the gas pedal while the car is stopped, you would have to press harder on the brake to keep the car from moving. This is because when you step on the gas, the engine speeds up and pumps more fluid into the torque converter, causing more torque to be transmitted to the wheels. The torque converter actually gives your car more torque when you accelerate out of a stop. Modern torque converters can multiply the torque of the engine by two to three times. This effect only happens when the engine is turning much faster than the transmission. At higher speeds, the transmission catches up to the engine, eventually moving at almost the same speed. Ideally, though, the transmission would move at exactly the same speed as the engine, because this difference in speed wastes power. This is part of the reason why cars with automatic transmissions get worse gas mileage than cars with manual transmissions.

To counter this effect, some cars have a torque converter with a lockup clutch. When the two halves of the torque converter get up to speed, this clutch locks them together, eliminating the slippage and improving efficiency.

After market Torque Converters:

On a daily driven Mustang, I highly suggest an after market torque converter. It will lower the overall gas mileage of the car slightly, but nothing too dramatically, unless you get crazy with the stall speed. I suggest the PI (Precision Industries) 3200 stall as the basis for a good all-around torque converter for a daily driver. If you are into all out high performance, then looking into a 4000 stall would be a good idea.

A torque converter is a great mod, but requires the install of a professional, which leads this to be an expensive mod. However, once in, you can expect close to a half second drop of your E.T.

Transmission Coolers:

Ok, now that we know what a torque converter is, and what stall speed is, we must know that a transmission cooler will be needed. The more time a transmission is at its peak stall point, the more excess heat its going to have. Overheating of the transmission is obviously a bad thing, and can reduce the life of the transmission dramatically. It puts added stress on all rings, bands, and clutches found inside the transmission, and allows the ability for air to enter the hydraulic circuit system. A transmission cooler is always a good mod to have, even if your car has the stock torque converter. But, if you do add an after market TC, you MUST add a trans cooler to reduce the excess heat it will create.

After market Transmission Coolers

I personally recommend B&M, and I suggest getting the largest transmission cooler made for your particular transmission, to ensure the best cooling efficiency.

Shift Kits:

Shift kits are a great mod for the racer wanting a firmer shift for their transmission. The shift kits duty is to increase hydraulic line pressure in the transmission and improve overall shifting. Its main duty is to reduce the lag time taken by automatic transmission during the shifts. The downside to shift kits is that the increased hydraulic line pressure puts extra stress on the bands and clutches, which can reduce the lifespan on the internals.

After market Shift Kits:

I suggest either Transgo or B&M for shift kits. Their products have been known to work well, and are pretty easy to install. Shift kits can be installed by someone with slight knowledge on transmissions, and can help ET’s by up to three tenths. A trans cooler is also a must have with a shift kit.

Valve Bodies:

Valve bodies are the brains of the operation when it comes to the transmission. The manual valve is what the shift lever hooks up to. Depending on which gear is selected, the manual valve feeds hydraulic circuits that inhibit certain gears. For instance, if the shift lever is in third gear, it feeds a circuit that prevents overdrive from engaging.

After market Valve Bodies:

This is not a mod for the average person. There is no reason to get a performance minded valve body unless your car is an all out drag car. It would make daily commuting a chore. It is something to add to the mod list in all out drag cars however.

Standard Transmissions

Clutches

The clutch is located inside the bellhousing. Its job is to enable the rear wheels to move by providing friction. For an explanation on how they work, go here.

The best clutch out there is simple – McLeod. They have the smoothest pedal operation, highest HP rating and seem to last the longest out of them all. These clutches are very expensive though and should only be chosen when your final mods are near. The second best clutch is also simple – Clutchmasters. Clutchmasters, along with McLeod are the only clutches out there that have been able to make 700-1000 HP clutches with the stock pedal feel. Like McLeod, Clutchmaster clutches are very expensive. The third best is Centerforce. Their pedal effort will increase with the higher HP clutches and might not wear as well but they are the best for the price.

The worst clutches are Ram and SPEC. Ram clutches don’t last long at all. SPEC used to be good but recently they’ve been having quality control issues. I’ve seen SPEC clutches pulled out after a few thousand miles and they look like glass! Not good… I recommend staying away from these brands.

To choose the proper clutch, you need to look at your expected HP when you’re all said and done. If you need a cheap and quick replacement clutch for a near stock car, King Cobra is a great choice. If you want to upgrade your clutch, look at your power you’re going to be making in the years to come and choose properly. Replacing the clutch can be very expensive ($400 worth of labor) so choose wisely.

Flywheels

The flywheel is located in the bell housing before the clutch. Its job is to receive power from the starter and spin the crankshaft to turn the engine over. When replacing a clutch, it is almost imperative that you resurface the flywheel. If the flywheel is warped badly, you need to replace it. After market flywheels are available for those of you who want more of a performance edge. A lighter flywheel like a billet or aluminum flywheel can provide the ability to rev quicker. This is great for a road racer but some drag racers might not like it. When launching, it won’t feel as hard as an iron one would due to inertia. Also, when selecting a lighter flywheel, you must relearn how to drive your car just like with gears. You’ll have to apply a little more throttle to keep it from stalling and revs might drop too quickly if you’re not careful. The flywheels I recommend are Fidanza, McLeod, and FRPP. They seem to make the quality ones out of the bunch.

Firewall Adjusters

Firewall Clutch Adjuster Installation: http://www.steeda.com/instructions/doublehook.htm

A firewall adjuster is needed whenever you install a clutch that is not OEM. Because of the stronger clamping force, the stock clutch quadrant cannot take the kind of pressure after market clutches place onto it. After market firewall adjusters allow for the clutch to be adjusted. You can set in the amount of play you want in the clutch with a firewall adjuster. Without this item, as well as the after market clutch quadrant, a clutch will eventually destroy itself and can possibly cause serious damage to the transmission.

Clutch Quadrants

Clutch Quadrants installation:

http://www.steeda.com/instructions/doublehook.htm

The stock clutch quadrant is self-adjusting. Over time you might notice that the clutch is getting a little too light, so you need to pull up on the clutch pedal and push it down hard a few times to get it back to normal. The stock clutch quadrant cannot be used with an after market clutch because the stock quadrant was never meant to handle that kind of clamping force. Steeda and UPR make some great clutch accessories for our cars; they are reasonably priced too.

Adjustable Cables

Adjustable Clutch Cable installation: http://www.steeda.com/instructions/doublehook.htm

Adjustable cables basically do the same thing firewall adjusters do; they allow for adjustment of the clutch’s engagement point. I personally feel they’re not exactly worth the money but if you want the maximum amount of clutch adjustment out there, Steeda offers a wonderful piece for our mustangs.

Shifters

Sample Shifter installation:

http://www.mustangworld.com/ourpics/fcar/shift1.htm

This should be the first modification for any manual transmission car out there. A new shifter will prevent you from over-extending a shift and possibly bending or breaking a shifter fork. Good after market shifters have “stop bolts” that prevent the shifter from breaking a shifter fork. Good ones are usually centered in the middle to allow for a smooth 2^nd to 3^rd shift and easy 3^rd to 4^th shift. Another great thing they do is take away all the slop that is apparent in the stock shifter. The ones I recommend are Pro 5.0, Steeda and the new one from MGW.