Tremec T-5 Five-Speed Transmission

[Bob_Spidell]

If you're taking a poll--and keeping your original 3.91:1 rear end--I'd vote for the 0.63 O/D gear. Putting a 3.54 rear end in my BJ8 made a big difference in freeway driving comfort, which we end up doing a lot of whether we like it or not (I don't). Some owners say the 3.54 with a 28% O/D--supposedly, the sun and planetary gears from the 4-cyls can be swapped--is even better. The only downside is I can't beat SRT Demons off-the-line anymore .

 

[WHT]

Hi Bob,

Well, I am open to recommendations (but, about to order).

We have a MGTD and you don't want to lug the engine at 2500 RPM.

My though was 4th gear provides 51 MPH at 2500 RPM and 61 MPH at 3000 RPM

I was going to order the 0.73 5th gear with our 3.91:1 differential and that yields 70 MPH at 2500 RPM and 84 MPH at 3000 RPM.

The 0.63 5th gear yields 81 MPH at 2500 RPM and 97 MPH at 3000 RPM. That seems like a very large gap between 4th gear and 5th gear?

I doubt we cruise faster than 80 MPH (2850 RPM with 0.73 gearing) and we would still have good acceleration without down shifting if needed in an emergency; looking at the torque band.

Is this bad thinking?


Regards, Bill

 

[HealeyRick]

Bill,

You mentioned wanting the T5 to make the Healey easier for your wife to drive. I think you might want to have her try out a Mustang with the T5 before making the leap. Mine is more difficult to shift than either the stock Healey or the Smitty's Toyota (I had one before installing the V8_ Admittedly, I installed a Steeda Tri-Ax shifter on the transmission to make it more positive shifting, so I can't compare directly to what Driven Man is offering. I'd just want to be sure it is going to meet your needs if you are going to spend that kind of money.

 

[Michael Oritt]

Michael, you didn’t mention the great time you had in my home town, Lompoc, CA. Give us a shout out.

Rob--

If you were one of the two fellows who supplied help and whose names I forgot long ago advice I owe you a long-overdue debt of gratitude for pitching in to help a stranger. Many many thanks to you and your compatriot.

 

[WHT]

Hi Rick,



Please Rick, say it ain’t so.

First, I very much appreciate your help and recommendations. But, this a little worrisome since earlier you said "I have this transmission in my BJ7, albeit behind a 5.0L Ford motor. It's a very good transmission and shifts nicely."

I also spoke with several people who said their T-5 Healey shifted very smoothly and they were quite happy with the installation.

Tremec says this about their product line: "Today, the T-5 still enjoys life as an original equipment unit in several overseas applications, while continuing to gain popularity in hot rod and performance markets. Dollar-for-dollar, pound-for-pound, the T-5 is the smoothest-shifting, and most reliable manual transmission for moderate horsepower applications."

Being more difficult to shift than a stock, worn, 54 year old Healey gearbox without a 1st gear synchro is not very reassuring (its actually frieghtening since I am about to order the transmission kit).

And, I don't know anyone with a manual Mustang who would let my wife drive it.

Its getting difficult to find a good, rebuildable W58 transmission. Heck, its even difficult to really know if it is a good core without tearing it down. Most people will not let you tear down their transmission before you buy it. Then, it costs about $1100 to have one completely rebuilt at a quality shop.

Regards, Bill

Bill,

You mentioned wanting the T5 to make the Healey easier for your wife to drive. I think you might want to have her try out a Mustang with the T5 before making the leap. Mine is more difficult to shift than either the stock Healey or the Smitty's Toyota (I had one before installing the V8_ Admittedly, I installed a Steeda Tri-Ax shifter on the transmission to make it more positive shifting, so I can't compare directly to what Driven Man is offering. I'd just want to be sure it is going to meet your needs if you are going to spend that kind of money.

 

[Bob_Spidell]

Hi Bob,

Well, I am open to recommendations (but, about to order).

We have a MGTD and you don't want to lug the engine at 2500 RPM.

My though was 4th gear provides 51 MPH at 2500 RPM and 61 MPH at 3000 RPM

I was going to order the 0.73 5th gear with our 3.91:1 differential and that yields 70 MPH at 2500 RPM and 84 MPH at 3000 RPM.

The 0.63 5th gear yields 81 MPH at 2500 RPM and 97 MPH at 3000 RPM. That seems like a very large gap between 4th gear and 5th gear?

I doubt we cruise faster than 80 MPH (2850 RPM with 0.73 gearing) and we would still have good acceleration without down shifting if needed in an emergency; looking at the torque band.

Is this bad thinking?


Regards, Bill

Well, silly me, I thought you were talking about a Healey BJ8 because your original post said 'We are considering installing a 5-speed transmission in our 1967 BJ8.' You switched gears on me .

With its 3.54 rear end and 22% reduction from its stock O/D my BJ8 gets around 2,500 at 75-80--I lost my gearing conversion chart--and it's quite happy at 2,500RPM (my car will start moving at idle in 4th on flat ground if I slip the clutch a bit). That's a 33% reduction in engine speed and, though I haven't driven a car so-equipped I've heard from owners it's an even better cruiser with the taller O/D gearing; taller than the 37% a 0.63 gives you). Note you're also 'giving up a gear;' 3rd-O/D isn't particularly useful but I'll sometimes use it around town when I don't feel like shifting or I want to test the O/D before I hit the freeway. But, it's your car and you're making a significant modification so get what you like.

FWIW, I had what I think is the predecessor of the gearbox you're considering in my '08 Mustang GT (a Tremec TR-3650). Owners complained that it wasn't smooth and I thought 3rd was a bit 'notchy' (why is it always 3rd?) I put synthetic gearbox fluid in it which helped a little. 5th was quite tall, and you could easily lug the 4.6L/310HP engine in 5th. Of course, it was a heavier car and had relatively less bottom end than a Healey 6.

 

[HealeyRick]

Bill,

By difficult to shift, I mean mine with an aftermarket shifter has a more positive, notchy feel than the Healey or Toyota. The well-worn cliche of rifle-bolt action applies. As I said, I don't know what a stock shifter feels like. I wanted the more positive feel and have read the stock shifter can be a little sloppy. I do think the T5Z shifter is an upgrade over the stock Mustang T5. You might call Driven and see if they can give you a number for someone who has done the Healey install and ask them.

 

[WHT]

Well, silly me, I thought you were talking about a Healey BJ8 because your original post said 'We are considering installing a 5-speed transmission in our 1967 BJ8.' You switched gears on me .

With its 3.54 rear end and 22% reduction from its stock O/D my BJ8 gets around 2,500 at 75-80--I lost my gearing conversion chart--and it's quite happy at 2,500RPM (my car will start moving at idle in 4th on flat ground if I slip the clutch a bit). That's a 33% reduction in engine speed and, though I haven't driven a car so-equipped I've heard from owners it's an even better cruiser with the taller O/D gearing; taller than the 37% a 0.63 gives you). Note you're also 'giving up a gear;' 3rd-O/D isn't particularly useful but I'll sometimes use it around town when I don't feel like shifting or I want to test the O/D before I hit the freeway. But, it's your car and you're making a significant modification so get what you like.

FWIW, I had what I think is the predecessor of the gearbox you're considering in my '08 Mustang GT (a Tremec TR-3650). Owners complained that it wasn't smooth and I thought 3rd was a bit 'notchy' (why is it always 3rd?) I put synthetic gearbox fluid in it which helped a little. 5th was quite tall, and you could easily lug the 4.6L/310HP engine in 5th. Of course, it was a heavier car and had relatively less bottom end than a Healey 6.

Hi Bob,


Sorry, I am talking about a 5-speed transmission for our 1967 BJ8 and I should have been clearer and not mentioned our TD. Please read this carefully and let me know what I am missing.

Many British 4 and 6 cylinder engines of this period were not designed to run for long periods of time at 2500 RPM or less; as would occur with our 3.91 differential gearing and a 0.63 5th gear. The harmonics can damage the crankshaft/bearings at sustained lower RPMs and the engine will run hotter. We like to run the engine closer to 3000 RPM.

And yes, modern engines are designed and built to run at 2000 RPM all day long. You can not compare a modern engine to a 54 year old British engine in this respect (either design or materials).

OPTION 1: As posted several times, the 0.63 5th gear with 3.91 differential gearing would cruise at 70 MPH at 2150 RPM, 81 MPH at 2500 RPM and 97 MPH at 3000 RPM according to the Spicer speed calculator. These are also the same numbers Driven gave me independently. So, they are either correct or we are both wrong.

This combination would force us to run the engine at 2150 RPM to cruise at 70 MPH in 5th gear; or we could run the engine at 3450 RPM in 4th gear. Running at 2150 RPM drops the engine out of its torque band and would not be beneficial to the engine in my opinion for long periods of time. Saving gasoline is not that important.

OPTION 2: The 0.73 5th gear along with our 3.91:1 differential gearing would allow us to cruise at 70 MPH at 2500 RPM and 80 MPH at 2850 RPM which is better IMO (plus it keeps the engine in a stronger torque band). And, we can still top 100 MPH when racing SRT Demons.

Again, if my numbers are correct, am I missing something? I am more than willing to accept my calculations are bad and should be corrected; and would appreciate your knowledge and help with this.

Please see the included speed calculations and torque band chart.

Thank you.

Regards, Bill

 

[WHT]

By difficult to shift, I mean mine with an aftermarket shifter has a more positive, notchy feel than the Healey or Toyota. The well-worn cliche of rifle-bolt action applies. As I said, I don't know what a stock shifter feels like. I wanted the more positive feel and have read the stock shifter can be a little sloppy. I do think the T5Z shifter is an upgrade over the stock Mustang T5. You might call Driven and see if they can give you a number for someone who has done the Healey install and ask them.



Hi Rick,

Thanks, that helps. I think the shifting will be OK for her. If not, there are aftermarket shifters that improve T-5 gate selection. There is a very active aftermarket parts/upgrade community dedicated to the T-5 transmission.

I posted on the two main AH Foruns hoping someone would have feedback on the kit, installation and shifting. So far, I am striking out.

Driven claims they have sold 50 kits; and I have asked them for names that I can contact to discuss their experience. Will see how that goes.

Heck, what else do you do at this point? I appear to be about 10 years too late for an easy Smitty transmission conversion (finding a good box locally) and have no wish to buy the Getrag conversion at current exchange rates. Spent the day searching for a good rebuildale W58 transmission that is close to me (for inspection) without much success.

In fact, there were a lot of people with different cars also searching for a good W58.

Regards, Bill

 

[Michael Oritt]

Hi Bob,

Well, I am open to recommendations (but, about to order).

We have a MGTD and you don't want to lug the engine at 2500 RPM.

My though was 4th gear provides 51 MPH at 2500 RPM and 61 MPH at 3000 RPM

I was going to order the 0.73 5th gear with our 3.91:1 differential and that yields 70 MPH at 2500 RPM and 84 MPH at 3000 RPM.

The 0.63 5th gear yields 81 MPH at 2500 RPM and 97 MPH at 3000 RPM. That seems like a very large gap between 4th gear and 5th gear?

I doubt we cruise faster than 80 MPH (2850 RPM with 0.73 gearing) and we would still have good acceleration without down shifting if needed in an emergency; looking at the torque band.

Is this bad thinking?


Regards, Bi

.

By difficult to shift, I mean mine with an aftermarket shifter has a more positive, notchy feel than the Healey or Toyota. The well-worn cliche of rifle-bolt action applies. As I said, I don't know what a stock shifter feels like. I wanted the more positive feel and have read the stock shifter can be a little sloppy. I do think the T5Z shifter is an upgrade over the stock Mustang T5. You might call Driven and see if they can give you a number for someone who has done the Healey install and ask them.



Hi Rick,

Thanks, that helps. I think the shifting will be OK for her. If not, there are aftermarket shifters that improve T-5 gate selection. There is a very active aftermarket parts/upgrade community dedicated to the T-5 transmission.

I posted on the two main AH Foruns hoping someone would have feedback on the kit, installation and shifting. So far, I am striking out.

Driven claims they have sold 50 kits; and I have asked them for names that I can contact to discuss their experience. Will see how that goes.

Heck, what else do you do at this point? I appear to be about 10 years too late for an easy Smitty transmission conversion (finding a good box locally) and have no wish to buy the Getrag conversion at current exchange rates. Spent the day searching for a good rebuildale W58 transmission that is close to me (for inspection) without much success.

In fact, there were a lot of people with different cars also searching for a good W58.

Regards, Bill

 

[Michael Oritt]

Bill--

I'll sell you my Smitty's conversion kit and Toyota five speed complete with BJ8 hydraulic clutch, custom FG tunnel, etc for $75,000 and will throw in the BN1 for free.

 

[Bob_Spidell]

re: "... Many British 4 and 6 cylinder engines of this period were not designed to run for long periods of time at 2500 RPM or less ..."

News to me, got a source? I've never thought of Healeys as being high revvers, and there appears to be a consensus that Healey 100 engines can become very unhappy over 4,500RPM:

Austin Healey 100 Crank Failures. – Precision Sportscar

www.netbug.net

My BJ8 has over 205K miles on its original crank, bearing straps and rods, about 145K miles often spent cruising comfortably around 2,500 give-or-take by me. At last rebuild, about 6K miles ago, the rods and crank mic'd standard (surprising me, as I'd already bought 0.020" under bearings).

Sounds like you want the shorter O/D; fine by me.

 

[WHT]

"I've never thought of Healeys as being high revvers, and there appears to be a consensus that Healey 100 engines can become very unhappy over 4,500RPM"

Your car runs 72 MPH at 2500 RPM with your gearing (3.54 rear end, W58 trans with 0.78 5th gear). So, this should not be a major problem for you.

The problem is, YOU are telling me to order a gearing combination for my car that will cause my engine to turn 2200 RPM at the same cruising speed. Then you become flippant when I simply asked you why that was a good idea.

Thanks, thats really great advice! Silly me, those are ideal conditions for an engine designed in the 1950s to ensure perfect oil pressure, lubrication, hydrodynamic oil wedge formation,coolant flow, cooling and reduced friction (NOT). My crankshaft and bearings will thank you.

BTW, your engine becomes sad over 4500 RPM because there are large, destructive third order harmonics as it nears 5000 RPM.

Regards, Bill

 

[Rob Glasgow]

Michael, no I was not one of the folks who helped you out in Lompoc. I just remembered you telling the story in a prior post a few years ago. Lompoc is off the beaten path so any mention of it gets my attention. Glad some locals were able to help you out.

 

[CraigC]

WHT, if you want information from a professional shop owner, contact David Nock of British Car Specialists in Stockton , Ca. He mentioned to someone on on of the Facebook Healey pages that they have done several. He did not mention any problems. He may even put you in touch with the customers so you can get their driving experiences and comparisons of before/after.

British Car Specialists

 

[Michael Oritt]

Michael, no I was not one of the folks who helped you out in Lompoc. I just remembered you telling the story in a prior post a few years ago. Lompoc is off the beaten path so any mention of it gets my attention. Glad some locals were able to help you out.

Rob--

The cluster broke in Lompoc and I merely drove down to Thousand Oaks in 1st->3rd->3rd OD on the 101. I met the anonymous helpers at Smitty's shop in the T-O area, but thanks for the potential helping hand had I needed one.

 

[WHT]

WHT, if you want information from a professional shop owner, contact David Nock of British Car Specialists in Stockton , Ca. He mentioned to someone on on of the Facebook Healey pages that they have done several. He did not mention any problems. He may even put you in touch with the customers so you can get their driving experiences and comparisons of before/after.

Hi Craig,

Thank you, that is great information!

I forgot about David and BCS and will call them Monday. They have been very helpful in the past.

We have been looking for direct feedback on the T-5 kit and had just about given up until your post. Really appreciate your help with this. They should have a good experience base to evaluate the Tremec installation with respect to the stock transmission and Toyota W58 converstions. And, if they installed several T-5 kits, a good feel for any problems that might occur with different cars.

Regards, Bill

 

[Bob_Spidell]

"I've never thought of Healeys as being high revvers, and there appears to be a consensus that Healey 100 engines can become very unhappy over 4,500RPM"

Your car runs 72 MPH at 2500 RPM with your gearing (3.54 rear end, W58 trans with 0.78 5th gear). So, this should not be a major problem for you.

The problem is, YOU are telling me to order a gearing combination for my car that will cause my engine to turn 2200 RPM at the same cruising speed. Then you become flippant when I simply asked you why that was a good idea.

Thanks, thats really great advice! Silly me, those are ideal conditions for an engine designed in the 1950s to ensure perfect oil pressure, lubrication, hydrodynamic oil wedge formation,coolant flow, cooling and reduced friction (NOT). My crankshaft and bearings will thank you.

BTW, your engine becomes sad over 4500 RPM because there are large, destructive third order harmonics as it nears 5000 RPM.

Regards, Bill

I'm not 'telling' you squat, I made a suggestion:

"If you're taking a poll--and keeping your original 3.91:1 rear end--I'd vote for the 0.63 O/D gear."

Since you disapprove of my suggestion, I'll gladly repay what you paid for it.

One more time, for posterity: It's your car, do what you want with it.

 

[HealeyRick]

Just something else to drive you crazy about the shifting action.

Here's my T5Z:

When I installed it I was able to center the shift directly below the hole in the tunnel and use an optional Mustang shifter (this is because I was positioning the engine/trnasmission combo so that it would work out this way and adjusted the motor mounts and engine position to suit:

Now note what Driven Man has done to get the same result, they have engineered an entirely different shifter mechanism, which looks like there may be an internal linkage between the shifter extending back to the shift tower itself. This would make shifter feel unique to that conversion. As you've said, "Ask the man that owns one".

 

[Guys small cars]

By difficult to shift, I mean mine with an aftermarket shifter has a more positive, notchy feel than the Healey or Toyota. The well-worn cliche of rifle-bolt action applies. As I said, I don't know what a stock shifter feels like. I wanted the more positive feel and have read the stock shifter can be a little sloppy. I do think the T5Z shifter is an upgrade over the stock Mustang T5. You might call Driven and see if they can give you a number for someone who has done the Healey install and ask them.



Hi Rick,

Thanks, that helps. I think the shifting will be OK for her. If not, there are aftermarket shifters that improve T-5 gate selection. There is a very active aftermarket parts/upgrade community dedicated to the T-5 transmission.

I posted on the two main AH Foruns hoping someone would have feedback on the kit, installation and shifting. So far, I am striking out.

Driven claims they have sold 50 kits; and I have asked them for names that I can contact to discuss their experience. Will see how that goes.

Heck, what else do you do at this point? I appear to be about 10 years too late for an easy Smitty transmission conversion (finding a good box locally) and have no wish to buy the Getrag conversion at current exchange rates. Spent the day searching for a good rebuildale W58 transmission that is close to me (for inspection) without much success.

In fact, there were a lot of people with different cars also searching for a good W58.

Regards, Bill

Question? did you ever come up with a good solution to an upgrade....I looked for anyone who has did the conversion ? did you find someone who has done it and what it cost?