Transmission / Overdrive: What's wrong with T86

[64studeavanti]

It seems like the T86 is getting bashed regularly on the forum. Now I can sure tell the difference in construction between a T86 and T10 (and I assume the T85), and I would not want to use the T86 for any high performance driving, but what is it about the T86 that is so bad when used in normal driving? After all Studebaker and probably others used this transmission for thousands of production cars. What breaks on a regular basis, what makes this transmission so unreliable? Any info from those who have this transmission in regular use? I don't want hearsay, rumors, or allegories, just the facts.

[candbstudebakers]

Nothing wrong with the T-86 just not as strong as the T-85 and is a 3 speed where the T-10 is a 4 speed some say the T-86 with over drive is a better unit than the T-10 for daily driving but not for racing, it is just a mater of to each his or hers own. And yes Studebaker did put a lot of them in there cars with the V-8's and I go along with them and their thinking, they were in business for a long time. some just can not leave well enough alone, nothing wrong with a good T-86

[bezhawk]

Had a T86 that the detent broke and got two gears at once! Not much left of that transmission. Split the case in two!
The weaker overdrive is also prone to locking up the freewheeling rollers if used behind a powerful engine.
Not only is the T85 stronger, the overdrive is also.

[Flashback]

A T-86 don't like Drag racing. It don't take a lot of horsepower, especially with wheel hop. All transmissions wear and things eventually happen. I have broken mine once. I was anxious to try it out. Had not traction bars (big deal with saving transmissions), and rear shockks were not on. 2500, drop the clutch, and wheel hop, and broken Trans. After rebuilding, 2000 miles, with several hard starts and it has been great. I said all this to say: For it's intended use, it's an excellent trans. If you are going to put a 250 up HP engine and wanna leave black streaks on asphalt, then do different.

[jackb]

...my take is if you're looking for horsepower and speed....dump the Stude stock stuff for your newer Big 3 alternatives.....but if you're enjoying the hobby and driving like yesterday, there's nothing wrong with stock components driven period correct. That T86 will suffer the same problems as the 27 R/A (and 44 for that matter), the door hinges, remote controls, light switches, etc......you gotta pay as you go or dump everything and buy a Toyota...

[64studeavanti]

I appreciate the thoughts. What brought this on is I have a project that will use a mildly warmed up 289. I have the choice of a T86 o/d or a T10. Now, if I wanted flat out performance, the T10 would be the better of the two but would still be weak for a high performance car. But, for normal driving - cruising, parades, etc - I think the T86 o/d may be a better choice given the price of gas. Of course one could 'upgrade' to TKO and other newer transmissions, but being a CASO, I like to use what I have.

[PackardV8]

First off, I love overdrives and agree they are far preferable to a T10 4-speed for everyday driving.

It seems like the T86 is getting bashed regularly on the forum.

Yes, the middle child.

No, nothing inherently wrong with the design.

Maybe, because many are now 50-70 years old and being used behind performance engine builds without being rebuilt itself.

When I was a teenager, I put many hard miles on a Flight Hawk with a T96 converted to floor shift and it never broke.

Next, I graduated to a Power Hawk with the T86 and a floor shift. Again, many hard miles and drag strip shifts. That tranny is still under the bench and needs a good home. The T86 does like a correctly adjusted and aligned shifter. Anything not as it should be and on the drag strip it can hang up and bad things happen. That's why Studebaker went to the T85/T89 with the many of the 289"s and the Packard V8. It is by far the strongest of the three overdrives.

Currently, I'm driving my '55 E12 with Packard V8 has a T89 and a floor shift. The truck version is noisy in low gear, but it won't break.

Bottom line - any problems with any of the Borg-Warner overdrives result from wear and abuse; nothing wrong with the basic designs.

jack vines

[StudeRich]

It seems like the T86 is getting bashed regularly on the forum./Cut/What breaks on a regular basis, what makes this transmission so unreliable? Any info from those who have this transmission in regular use? I don't want hearsay, rumors, or allegories, just the facts.

I don't believe the T-86 has actually been "Bashed" here for regular use for which it was designed, as Jack and others have said, the only problem is when it is used behind a R1 or stronger Engine, THEN you will have early failure if driven harder than your Grandmother did.

The T-85 is the base Trans. for the T-10, and both are very strong and not likely to fail in good condition up to 4 or 500 HP.

As to the weak points in the T-86 it is often the Sycros and the Syncro teeth on the Second and High Gears, also the Input Shaft Needle Bearings and Inside of the Input Shaft where same reside. Then there is the R-10 Overdrive, not as strong as the R-11 Used on the T-85.

[64Avanti]

I broke 2 T86's with overdrive in a modified 60 Hawk and gave up and installed a T85 with overdrive. I broke first gear in the T86 and found that the 2nd syncro didn't like fast shifting. I also modified the electrical so that I could use 2nd overdrive.

[StudeRich]

/Cut/I also modified the electrical so that I could use 2nd overdrive.

You got my attention on that one! Why would your Trans. not go into 2nd. Over without WHAT Mod.?

All I have ever owned or driven went into 2nd or 3rd. O.D. by releasing the Go Pedal, and even LOW if I wanted to beat it up a bit!

[PackardV8]

The usual modification is to move the kickdown switch or add a second manual switch in parallel so the downshift can be accomplished at part throttle or so one can run through all six gears going up if desired.

FWIW, on one car with a floor shift conversion, I mounted the kickdown switch under the hood where it could be actuated by the shifter fork on the steering column. Not the most convenient and I wouldn't do it that way again.

jack vines

[kxet]

You can kick down od by turning ignition switch off and on quickly.Don't have to back off. You can ground the govenor wire with a switch and go into od any time except in reverse. I mounted the off-on switch on floor shift handle. Then you turn said switch off to kick down. I imagine taking off in 1st od is hard on things in smaller od unit,they break easy. Did this in old days with Fords and 55 Studebaker. Parts were easy to get in the 60s for ods. A T-10 and t-85 probably share some internal parts,look similar. I also switched 6volt to 12 volt without frying solenoids on 54 Ford and 55 Studebaker,these were generators, not alternators. Wouldn't recommend it.Parts were all over in wrecking yards.Have fun.

[unclemiltie]

We have to remember that the T86 was used behind the Commander big 6 engines. It works great in my 50 Commander. Studebaker then used this same transmission in the 232 V8's and then behind the 259's and 289's. I have also had T86's in various V8 Studebakers without any issues but I never tended to push them very hard.

[PackardV8]

A T-10 and t-85 probably share some internal parts,look similar.

Yes, bearings and synchro rings.

No, no gears or shafts.

jack vines

[64Avanti]

You got my attention on that one! Why would your Trans. not go into 2nd. Over without WHAT Mod.?

All I have ever owned or driven went into 2nd or 3rd. O.D. by releasing the Go Pedal, and even LOW if I wanted to beat it up a bit!

Well it has been about 43 years since I had that 60 Hawk with overdrive. I think that I had a switch to bypass the governor so that I could shift into overdrive without reaching the governor speed. I don't remember the governor speed but I think it was somewhere between 25 and 28 mph.

I had modified the intake manifold to take an AFB. There was a Buick AFB that was fairly small. I had also used an R1/R2 cam and some mild port work and had milled the heads to get to about 9.7 compression ratio with the dished pistons. On the highway at about 70-75 mph I could get about 24 mph. Hurst even had a shifter that fit the T85!