| Author | Message | ||
| Ken (Allyn)
Member Username: Allyn Post Number: 525 Registered: 10-2001 |
Great story! My 72 Lotus uses 80 wt. gear oil. I didn't realize newer cars use such light oil! | ||
| Dan B. (Dan_the_man)
New member Username: Dan_the_man Post Number: 25 Registered: 9-2002 |
thirty plus years ago 80 to 90 wt gear oil was used in trannys. then they (as one of you stated) changed to ATF for clearance reasons. ATF is NOT a lubricant! ATF is a hydraulic fluid. it does not act as a degreaser and it does not flush the engine. Diesel fuel was (and for some old timers still is) used to flush engines much like Marvel Mystery Oil (and other engine flushes) is used today. Some people would add it to the oil and run it before changing, but the main way for Diesel Fuel was to drain the oil, fill with diesel fuel, and let run for several minutes. Diesel fuel, gas, and motor oil have the same basic make up. Thus it would lube enough to main tain clearnce at idle. Due to tighter clearances and better gear design (pitch angle etc) ATF has been used in manual trannys for some time. It has much lower Viscosity and thus creates less resistance and thus less heat than a heavier gear oil. Actually if you tried a heavier gear oil (or some people suggest 50 wt motor oil) in your tranny your would immediately see a harder shift (due to clearances) and higher heat along with more resistance. (you probably would not notice the resistance but it would be there) | ||
| Verell Boaen (Verell)
Member Username: Verell Post Number: 410 Registered: 5-2001 |
Used to have a '91 Probe LX with the same V6 as the Ford Taurus. It's 5-speed manual tranny used ATF. That's the 1st time I ever ran into ATF in a manual trans. Sure surprised me. | ||
| Hans E. Hansen (4re_gt4)
Member Username: 4re_gt4 Post Number: 286 Registered: 4-2002 |
What Rob said is true. Lots of GM manual gearboxes use ATF. The progression to thinner oil in gearboxes has been gradual. 20W was used in a number of boxes. This has to do with clearances being tightened up considerably. Cute story: 1985 Z28 Camaro. Owner called wondering what to put in his gearbox. We told him that the books call for 20W engine oil. He didn't believe us, and used 90W. Car came in next day on the hook. Drive train completely froze up. We took out the tranny (Borg Warner T-5?? if I remember correctly), and you couldn't turn it at all. Drained out 90W grease, filled with solvent. Shook like a martini, and managed to turn it by hand eventually. Emptied out solvent, added 20W and embarressed customer went down the road. | ||
| magoo (Magoo)
Advanced Member Username: Magoo Post Number: 3232 Registered: 2-2001 |
Also some cars use ATF in the final drive as well as the auto trans. | ||
| Rob Lay (Rob328gts)
Board Administrator Username: Rob328gts Post Number: 2373 Registered: 12-2000 |
Many manual gear boxes recomend ATF anyway, I think. I'm not technical enough yet to claim anything, so any posts I do in Technical Q&A will always end in "I think".  | ||
| Mark (Markg)
Member Username: Markg Post Number: 285 Registered: 2-2001 |
In the 'old' days before synthetic gear oil I know adding a little ATF to the gear box made it shift quicker for RACING - NEVEr on a daily driver....! | ||
| Dave Penhale (Dapper)
Member Username: Dapper Post Number: 276 Registered: 4-2002 |
Doesn't deserve to own the car period. | ||
| Verell Boaen (Verell)
Member Username: Verell Post Number: 407 Registered: 5-2001 |
Bill, I believe ATF is about a 5w oil. So probably you didn't do anything that running Castrol SYNTECH 5w50 wouldn't do better. Back in the early '60s when I 1st got into cars, folklore had it that you could thoroughly desludge an engine if you ran it until thoroughly hot, addes a couple of quarts of Diesel fuel & let it idle for a couple of minuites before draining the oil. Might have done more good than bad back before the days of high detergent oils that keep your engine pristine if you change them regularly. Not something I'd recommend today tho. | ||
| Bill Sebestyen (Bill308)
Member Username: Bill308 Post Number: 377 Registered: 5-2001 |
I have on occasion added a quart of tranny fluid to some engines to clean them but only let them run for about 15-minutes at a fast idle and no load. This was followed by a complete drain and refill with the appropriate oil. There were no noticeable ill effects but I'm not sure how much good it did either. | ||
| jeff ryerson (Atheyg)
Junior Member Username: Atheyg Post Number: 62 Registered: 8-2002 |
I dont know about tranny fluid in the oil but I put about a quart in my fuel tanks for my diesel trucks it cleans the fuel injectors and injection pump, maybe he thought a 911 has a diesel engine. | ||
| Greg Rodgers (Joechristmas)
Member Username: Joechristmas Post Number: 494 Registered: 3-2001 |
That story is great. Whoever wrote it made it hilarious. | ||
| Lawrence Coppari (Lawrence)
Member Username: Lawrence Post Number: 309 Registered: 4-2002 |
I have heard about people putting tranny fluid in their crankcase to clean their engine. Here is a post from a Porsche list. Well, a slow day in the shop today - until a customer (who shall be known as dumbass) came in with his car (996 Carrera 4) on a towtruck. Dumbass states that his car mysteriously "stopped running" while he was on a high speed run along I-95. As I am the junior mechanic (meaning I have 10 years experience, as opposed to the other guys haveing 15+) I am told to "troubleshoot" Great!, don't see too many 996's, as most of them are still under factory warranty so they go the the dealership for repairs. Visual inspection of the engine shows some heat discoloration - hmm... Coolant tank shows the dreaded "chocolate malt" Something is wrong here - it almost looks like a "chocolate/strawberry malt" Car has less than 5k miles on it - no stamp in the book for an oil change - we stamp the books too - we can't use the Porsche stamp though. Pull the dipstick - same thing - oil is at correct level - notice a band of red fluid at the upper end of the dipstick. ((PUZZLING - but getting a vague sinking feeling)) Drain oil - hmmm...it just doesn't look right - then again all of those metal flakes shouldn't be there... but the oil just looks "Wrong" Smells burned. Take dumbass into the office. Ask him to describe what happened, what he was doing, what did his gauges read, any odd noises (some of you may recognize these questions - I ask them here a lot) Dumbass states that nothing out of the ordinary until about 2 minutes before the car stalled - engine temp spiked. dumbass then added that car has not run right since he changed the oil.... I ask "really, tell me about your oil change" dumbass states that a friend told him you can desludge an engine (mind you less than 5000 miles on odo.) by running transmission fluid through the engine!!!!!! I ask dumbass to go on. Dumbass states that when he changed the oil, he put 2 quarts of oil, and 5.5 quarts of transmission fluid in the engine. He did this to desludge the engine. At this point, I excuse myself and get the owner. Fill him in on situation. Owner talks to dumbass, I drop the oil pan. End result, as you have probably gathered by now - engine is TOAST. With a big grin, gave the customer the diagnosis and the estimate. $15,000 to rebuild (and you think 944 parts are expensive!) - that is assuming nothing else pops up. or he can just give us $35,000 and we can order him a new engine. there are sportscar owners, and then there are people who own sportscars. Dumbass is thinking about it - will call on monday. |