like other special-interest groups -- are forever forming organizations to focus on common problems.

But few have been as successful as DDOG (Disgrunted Diesel Owners' Group Inc.), a Vienna-based organization celebrating its first birthday and the recovery of several million dollars for members who have had problems with General Motors diesel-powered cars and light-duty trucks.

The cash compensation and repairs, according to DDOG president Joyce Arndt, include:

*More than $3 million in cash and replacement parts for the vehicles of about 2,300 members.

*Offers of cash compensation or free repairs for about 2,000 members' vehicles. The offers average $1,500 per vehicle.

*New diesel engines at reduced or no cost for about 500 members.

Such success is remarkable for a consumer group seeking redress of automobile problems, according to Clarence Ditlow, director of the Center for Auto Safety, a Washington public-interest group.

"You can get GE to take back your toaster, but to get GM to take back your diesel -- or make good on the one you have -- is another story," Ditlow said. "This group not only took on GM, they took on GM and they won."

Ditlow said that DDOG had managed to do better for its members than the Federal Trade Commission, which last year settled its administrative action against GM by signing an agreement with the company to have consumer diesel car and truck complaints resolved through an arbitration program sponsored by the Better Business Bureau.

The lesson for all consumers in the DDOG success, Ditlow said, is that "the more you join with other people with the same problem, the greater the chance of success. Because," he said, "the people who joined DDOG had already approached GM with their problems and been turned down. As individuals they were unsuccessful; as a group, they were very successful."

Ditlow said DDOG had gotten results because "they were a very abused group of consumers who were very articulate and outraged, and when you combine that outrage with the dollar amount they had at stake, it gave them the incentive to stay at it and win."

Working as DDOG, the diesel owners pooled their money -- membership cost is $20 -- and hired two public-interest lawyers to negotiate their case with GM. That negotiation led to an agreement on July 26, 1983, in which GM said it would establish a special process to handle claims for DDOG members who had faulty GM diesel cars and light trucks.

GM has manufactured more than 1 million diesel-powered cars and light trucks since 1978. Owners of the diesel vehicles have reported serious problems including blown head gaskets, cracked blocks, defective fuel injector pumps, oil leaks that cannot be repaired despite repeated attempts, broken camshafts and crankshafts, and bad transmissions. Repairs have cost as much as $8,400, with repair bills of $3,000 to $4,000 not uncommon.

The announcement of DDOG's victory in obtaining the special claims-handling process was followed by an announcement by GM that it would give individual owners of GM diesel vehicles the same treatment on repair claims that it was giving to DDOG members.

"Anyone coming to us with a problem is entitled to the same treatment as a member of the consumer group," said William H. Noack, GM public relations manager for the Washington area.

DDOG officials agree that all diesel owners, whether or not they belong to DDOG, can apporoach GM for assistance with their problems at any time. However, they said, "those interested in cutting through the red tape may still join DDOG for advice on how best to submit diesel claims to GM" by sending their name, address and a check for DDOG's $20 membership fee to DDOG, 316 Dominion Rd., Vienna, VA, 22180, or calling 281-1601.