Posted on

Signs of a Bad Torque Converter

If you drive a vehicle with an automatic transmission, then chances are you have a torque converter and don’t even know about it. Of course, you probably wonder just what a torque converter actually is, simply because it’s not really a topic of a dinner conversation.

The best analogy for a torque conversion part would be that it is basically doing the same work that a clutch does in a manual transmission. This part will essentially keep the engine running when the wheels come to a stop. If this torque part does its job, you won’t even notice it. However, if it is going bad, then you will have some serious problems. Luckily, there are plenty of signs that will help you tell if your torque is going bad.


Signs of Torque Converter Problems

There are many signs that your torque converter is starting to have problems. One major concern would be engine overheating. If you are noticing that the temperature gauge is exhibiting strange fluid pressure, it could be a symptom of bad torque.

Another sign that this part is going downhill would probably be slipping. If you are driving along and you occasionally notice your acceleration dropping considerably, it could be a sign of this part going out on you.

If your vehicle appears to shudder when you are driving between 30 to 45 miles per hour, this could be another sign. If you have checked the engine fluid and there are large amounts of black materials present, that too could also be a sign your torque is faltering.

Finally, if it appears that it is taking the transmission longer to engage the engine and if you are hearing a number of strange clicking or revving sounds, then it might be time to replace a bad torque converter.


How to Test for Torque Converter Problems

In some older vehicles, you could do what is called a stall-speed test. In this procedure, you simply rev up the engine for no more than five seconds while you also have the brake pedal fully pressed down to the floor. Make sure not to do this for more than five seconds, and be sure to avoid this type of test with vehicles that have traction control or anti-lock braking system.

Another procedure would be to first let the engine warm up for about five minutes, then gently press on the accelerator while the vehicle is in the park position. Let the engine go back to idle and then immediately shift it into drive and listen for any abnormal sounds. Finally, take the vehicle for a quick test drive and see if there is any unusual sounds or lurching movements.


Causes of Torque Converter System Problems

Different parts can play a role in causing a torque converter system to break down.

First of all, one item to consider would be the needle bearings. If these bearings fail, it could cause some metal to metal contact and might make the whole entire system fail. A damaged torque system seal will usually mean that fluid will leak from the casing. If this happens, you can rest assured that your torque system will either overheat, slip or have irregular gear shifting.

If you have a damaged clutch, it can overheat the gears and make them stay in gear at all times, even when you don’t want them to be in gear.

Finally, if the solenoid malfunctions, it can cause an uneven pressure rotation in your torque system.


Torque Converter System Replacement

One of the trickiest things about repairing a torque converter system would probably have to be the fact that replacing it is often quite a bit less expensive than replacing it. Talk to your mechanic to discuss your options, but realize that a total replacement can often lead to a smoother ride in your vehicle and a system that is more durable overall.


Tips on Picking a Torque Converter

Finally, picking a torque conversion should be considered as well. In short, go for one that will have a maximum of 500-750 RPM’s. Finally, realize that most compact cars will do best with a 2400 RPM conversion system.


Keep this information in mind and you are sure to be wholly prepared if you ever have a bad torque converter issue with your vehicle.




Posted on

4R100 Transmission Spotlight

4R100 Transmission Spotlight

The Ford E4OD and 4R100 four-speed automatic transmissions were basically the same exact transmission, just with different names. The Ford E4OD transmission was updated in 1998 to the newer 4R100. Both the E4OD and 4R100 were electronically controlled transmissions, replacing the C6’s hydraulic-controlled system. To follow Ford’s new naming schemes for its other transmissions, Ford eventually renamed the E4OD as the 4R100 and the release of Ford’s Super Duty in 1999 kick-started an explosion of aftermarket performance parts for the revamped 7.3L Power Stroke. The 4R100 automatic transmission was mostly similar to the earlier E40D, but with some key changes to internal components in order to increase its durability when installing behind the popular Power Stroke Diesel Engine. In 1999, the 4R100 was fitted with a PTO for auxiliary equipment attached to heavy-duty trucks.

The 4R100 also matched Ford’s big 7.3-liter Power Stroke diesel engines from 1999 through 2003. The 4R100 reflected Ford’s new identification system for its transmission lineup, but it also solved some problems associated with the older E4OD. While the E4OD transmission problems were not decidedly major or even widespread, Ford developed the newer 4R100 with specific plans to resolve these issues. Even the 4R100 had its own problems, failing to maintain the increased torque output of the bigger engines available at the time. Aftermarket 4R100 modifications seemed to solve the issue by raising its torque capacity to over 1,000 foot-pounds. Among the aftermarket modifications were a high-performance shift-kit and power valve, along with a heavy-duty clutch. In 2004, when the 6-liter Power Stroke engine eventually replaced the 7.3-liter version, the Ford 4R100 transmission disappeared with it.

Ford reserved the 4R100 transmission for performance trucks and heavy-duty sport utility vehicles. The E4OD and 4R100 were huge transmissions at 27.25 inches long and not easily applicable to non-Ford trucks and vans. Shoehorning the transmission into another vehicle requires extensive modifications. They decided to match the transmission with engines in:

  • the 1999 to 2004 Ford SVT Lightning high-performance truck,
  • the 2002 to 2003 Ford F-150 Harley Davidson Special Edition,
  • the 1999 to 2003 Ford F-250 and larger Super Duty trucks,
  • the 1999 to 2003 Ford Expedition SUV equipped with the 5.4-liter V-8,
  • the 2000 to 2003 Ford Excursion, and
  • the 1999 to 2004 Ford E-Series vans.

The gear ratios for the E4OD and 4R100 transmissions were identical, with the 4R100 having a step 2.71 first gear that’s great for trucks towing a heavy load. The overdrive gear ratio is 0.71, which can help improve the fuel efficiency of this large diesel motor. The second gear ratio is 1.54, with the third gear ratio being a straight 1:1 ratio.

The 4R100 is a computer controlled transmission, which gives the truck owner the option of using a handheld controller to modify the characteristics of the transmission. The firmness of the shifts, line pressure, and RPM at which the transmission shifts is all adjustable with a handheld tuner. The transmission can even be reprogrammed to compensate for larger diameter tires.

Posted on

200-4R Transmission Spotlight

200-4R Transmission

For the 1981 model year of General Motors vehicles, the 200-4R transmission was introduced in 1980. The 200-4R is the lesser known of the two overdrive transmissions made by General Motors in the 1980’s, but they are still considered part of the Turbo-Hydramatic series that began in the 1930’s.The components were prone to failure in the earlier TH200 model and were improved in the later 1980’s with this line of transmissions. The 200-4R transmission was used with high-power applications, especially the Buick Grand National and the 1989 Pontiac Firebird Trans Am Indy 500 Pace cars. The TH200-4R was configured with several different torque converters and gear ratios, depending on the vehicle application. Many of the vehicles out there that still exceed 700 horsepower are still using the TH200-4R transmission to this day.

Unlike the 700R4, most 200-4Rs have a multi-case bell housing for use with Chevrolet, Buick, Oldsmobile, Pontiac, and Cadillac engines, but the 200-4R shares mounting placement with the TH-400 transmission. Since the outside dimensions are close to the TH-350 transmission, 200-4Rs are often swapped in place of TH-350’s in older vehicles to provide an overdrive gear.

The external dimensions are similar to the Turbo 350 so it is often swapped in older vehicles to provide an overdrive gear. In addition, it has a multicase bell housing for use with Chevrolet, Buick, Oldsmobile, Pontiac, and Cadillac power plants, although the TH200-4R was phased out after 1990. Early models had PRND321 on the cluster, while later models had PRN(D)D21, with the left D identified as the overdrive gear by a square or oval ring.

The TH200-4R transmission, like the TH-350, uses a 27-spline output shaft, which is similar in length to the TH-350 and the TH-200 models, making it a top selection for many overdrive conversions. The TH200-4R transmission is also similar in length to the Powerglide and the Pontiac Super-Turbine 300, which makes it a popular model for converting from a two-speed to a four-speed automatic.

The TH200-4R transmission has a 2.74:1 first gear ratio, with overdrive being 0.67:1. It has an oddly-shaped 16-bolt pan with 13mm bolt heads. The TH200-4R was primarily used in GM rear wheel drive cars that were equipped with the 231 Buick, 301 Pontiac, and the Oldsmobile 307, 350 gas and diesel engines between 1981 and 1990. Many Chevrolet 267 and 305 V-8 engines also came with the TH200-4R transmission because of the multi-fit bell housing. You can still find a TH200-4R transmission in any of these cars:

  • 1981-’90 Cadillac Fleetwood, Deville and Brougham
  • 1981-’88 Buick LeSabre, Electra RWD, Chevelle, Monte Carlo, Malibu & El Camino
  • 1982-’90 Chevrolet Impala, Caprice, Olds Delta 88, 98 & Custom Cruiser
  • 1984-’87 GMC Caballero & Pontiac Grand Prix
  • 1983-’88 Olds Cutlass 442 & Supreme
  • 1983-’89 Pontiac Bonneville, Parisienne & Safari Wagon
  • 1981-’87 Buick Regal
  • 1981 Buick Century & Pontiac Firebird 301

The best TH200-4R transmissions to mount in your vehicle, if you’re looking for performance-grade parts, are typically the units manufactured for the Buick Grand National, Oldsmobile 4-4-2 and Chevrolet Monte Carlo SS during 1986-’87 because this model used a special valve body, a larger reverse boost valve, second to third intermediate servo, and a specially manufactured governor assembly.