Post by Old Techo on Apr 9, 2023 11:46:19 GMT 10
I have rebuilt several manual and auto boxes but no auto with more than 3 forward gears nor any manual with more than 5 forward gears.
This may be of general interest from Quora...
In the long run, would a manual transmission have fewer issues than an automatic transmission?
Ralph, I’ve been working in the Transmission business all my working life, it’s a rewarding interesting field of work and the pay’s not bad either, on to your question.
Both an automatic and a manual transmission have their weak points and strong points. I personally have a 5 speed manual in my Toyota Tacoma and I may be one of the last people in the world to have one. lol
The manual transmission’s weak point is the clutch, just think, every gear change the clutch is released and re-engaged, in the course of a 15 minute rush hour commute that could well be a hundred times. Depending on how you drive and are concuss of how you use the clutch it can last you a long time. I just replaced mine at 95 thousand miles, about normal for me, otherwise a manual transmission is pretty simple and reliable.
To make it so people don’t have to shift requires a very complex system. We’ve had automatic transmissions available to the driving public since 1948, and since then at least one new/better model transmission was released by somebody every year.
Today the car industry is under tremendous pressure to make the cars burn less fuel and put out less pollutants/emissions. Although this is mostly an engine issue, the transmission gets to help by keeping the engine in it’s most efficient RPM zone. To do that, we’re going to have to add a few gears and make them even more complicated.
Transmissions for a long time had only 3 forward gears for automatics and 4 for standard shift, then came the 70’s fuel crunch and each received an overdrive gear. It stayed like that for a long time, where the only new changes was in the way they stuffed the transmission under the hood.
That brings us to today, the transmission now has to provide the engine with enough gears to keep it’s RPM range at optimal efficiency (that’s only about a 2,000 RPM window) that forces some car manufactures to designed their automatics with up to 9 speeds or gears all computer controlled to keep engines in that range.
How does that relate to your question, well an automatic doesn’t have a single clutch, it has a lot of them only smaller, any number small clutches working together can equal one large clutch, this is called a “clutch pack” in a modern transmission there are several “clutch packs”inside the transmission and usually there are at least 2 dedicated for each gear, these clutch packs work much the same as your manual transmission’s clutch, engaging and releasing with each gear change. With 9 speeds/gears to control that’s a lot of shifting, but the transmission is designed to handle it. On the other hand, manual transmissions now have 6 speeds/gears that’s a lot of busy work.
Service the manual transmission, (change the oil) at a 3 to 1 engine oil change ratio.
Technically to answer your question, I’d have to give a conditional yes, that condition is the driver, a bad driver can wear out a manual transmission’s clutch in no time, or burn up a similar clutch pack in an automatic.
Then on the other hand, I’ve seen properly maintained automatic transmissions go 200,000 miles or more. The key here is properly maintained and driven, that means you are going to have to physically take your car into the shop and get it serviced at least once a year, (NO MATER WHAT YOUR SERVICE MANUAL SAYS), there is no such thing as forever fluid, changing fluid has been proven to be the necessary key to an automatic's long life.
A manual transmission needs very little maintenance during it’s life, with either transmission, look for leaks, these transmissions depend on their fluid for a normal life, if you want either type of transmission to last a long time, get the leaks fixed as soon as you see them.
Kind of windy but I hope this answers your question.