Auto Tranny Saga - Help for the Record
Auto Tranny Saga - Help for the Record
94 Touring - Auto
Koyo, downpipe, everything else stock
Been off the forum for a while - largely because the 7 has been on stilts in the garage.
I am posting for the record. Perhaps this will help some others someday.
Built the engine back to stock because I wanted the auto trans to live a long life. Rumor is that a stock one is good for 350 HP. The one that came with the car lasterd about one year. I have no idea how many miles on it. Possibly over 100k. When it failed, it started to slip one morning. Limped it home and later swapped it out of a 30,000 mile stock tranny.
It felt and ran good, but also died shortly thereafter. Maybe 5000 miles at most. I am a moderate driver at best. I do not trash the car because I do not like laying under it. The second tranny made a horrible noise and did not go into gear, so I pulled it.
Bought a third tranny off the forum from a local. Supposedly is was a $4000 rebuild from Level 10 transmission. Supposedly new with a brand new stall convertor. I bit... got it cheap becasue the guy was doing a manual swap.
Put it in, the convertor was too thick and it damaged the front seal in the tranny. Leaked all over everywhere. I pulled it out, change the seal and smoothed up the welding flash on the convertor that cut the seal.
Tranny lasted about 200 miles. Towed it home.
I took all three trannys to A&A Transmission in Indy. These guys have a good rep with racing transmissions and one person there is a Jatco guru. Here is what I have learned.
The trannys are notorious for the pins walking out of the planetary gears. They have a high pressure issue at highway speeds (where I did most of my driving), and the material used in the stock convertors has a tendency to dissentigrate and wind up in the cooler or pan filter. In all three trannys, the pins were loose, includinig the low mile one. All three have convertor failure. It is possible that the previous failures left debris in the coolers, which exacerbated the failures of the following two. I blew the cooling system out each time, but that was not sufficient. You have to pull all coolers and hi-temp pressue clean (FYI).
All the trannys showed signs of slipping on the clutches and steels. The steels were burnt on the third gear.
I got a stall from a professional race builder in California. He replaced the suspect materials in the covertor clutch with high end materials and rebuilt it. Cost was around $480, which I think it was money well spent. Anyone looking at building up an auto probably should consider this as mandatory.
The planetary can be welded to hold the pins. I suggest doing this also to prevent higher mileage failures on your new expensive rebuild.
There are aftermarket shift kits that improve the high pressure issue with this tranny. This is not a concern for race cars (that are driven little), but is for cars that are going to be driven alot on the highway. The high pressure can damge the internals..I am noting this here, not as a expert but something that you should check out if you ever repair or rebuild one.
Also, stay away from Level 10. The internet has a ton of bad press on them and this tranny I had was built very poorly. The reliability improvements were not done and it looks like they reused too many old stock parts. Supposedly this was their high end rebuild. The pins in the planetary gears were about ready to walk out. Again, it lasted less than 200 miles....
One more thing. Make sure you buy a very high quality (OEM) filter. The aftermarket ones we found to have leaks around the seam. When we pressure tested, the filter sucked air... very bad...Also, all three trannys had the o-ring cut on the filter from improper installation. This is something that is a big concern. Whoever installs your filter needs to pay close attention not to damage the ring.
Cost was about $2350 for everything, tax included. I think the Mazda replacement was $2500, but no stall and standard components....I would not suggest going that route in light of the improments that need to happen.
Koyo, downpipe, everything else stock
Been off the forum for a while - largely because the 7 has been on stilts in the garage.
I am posting for the record. Perhaps this will help some others someday.
Built the engine back to stock because I wanted the auto trans to live a long life. Rumor is that a stock one is good for 350 HP. The one that came with the car lasterd about one year. I have no idea how many miles on it. Possibly over 100k. When it failed, it started to slip one morning. Limped it home and later swapped it out of a 30,000 mile stock tranny.
It felt and ran good, but also died shortly thereafter. Maybe 5000 miles at most. I am a moderate driver at best. I do not trash the car because I do not like laying under it. The second tranny made a horrible noise and did not go into gear, so I pulled it.
Bought a third tranny off the forum from a local. Supposedly is was a $4000 rebuild from Level 10 transmission. Supposedly new with a brand new stall convertor. I bit... got it cheap becasue the guy was doing a manual swap.
Put it in, the convertor was too thick and it damaged the front seal in the tranny. Leaked all over everywhere. I pulled it out, change the seal and smoothed up the welding flash on the convertor that cut the seal.
Tranny lasted about 200 miles. Towed it home.
I took all three trannys to A&A Transmission in Indy. These guys have a good rep with racing transmissions and one person there is a Jatco guru. Here is what I have learned.
The trannys are notorious for the pins walking out of the planetary gears. They have a high pressure issue at highway speeds (where I did most of my driving), and the material used in the stock convertors has a tendency to dissentigrate and wind up in the cooler or pan filter. In all three trannys, the pins were loose, includinig the low mile one. All three have convertor failure. It is possible that the previous failures left debris in the coolers, which exacerbated the failures of the following two. I blew the cooling system out each time, but that was not sufficient. You have to pull all coolers and hi-temp pressue clean (FYI).
All the trannys showed signs of slipping on the clutches and steels. The steels were burnt on the third gear.
I got a stall from a professional race builder in California. He replaced the suspect materials in the covertor clutch with high end materials and rebuilt it. Cost was around $480, which I think it was money well spent. Anyone looking at building up an auto probably should consider this as mandatory.
The planetary can be welded to hold the pins. I suggest doing this also to prevent higher mileage failures on your new expensive rebuild.
There are aftermarket shift kits that improve the high pressure issue with this tranny. This is not a concern for race cars (that are driven little), but is for cars that are going to be driven alot on the highway. The high pressure can damge the internals..I am noting this here, not as a expert but something that you should check out if you ever repair or rebuild one.
Also, stay away from Level 10. The internet has a ton of bad press on them and this tranny I had was built very poorly. The reliability improvements were not done and it looks like they reused too many old stock parts. Supposedly this was their high end rebuild. The pins in the planetary gears were about ready to walk out. Again, it lasted less than 200 miles....
One more thing. Make sure you buy a very high quality (OEM) filter. The aftermarket ones we found to have leaks around the seam. When we pressure tested, the filter sucked air... very bad...Also, all three trannys had the o-ring cut on the filter from improper installation. This is something that is a big concern. Whoever installs your filter needs to pay close attention not to damage the ring.
Cost was about $2350 for everything, tax included. I think the Mazda replacement was $2500, but no stall and standard components....I would not suggest going that route in light of the improments that need to happen.
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