5-speed "deep thoughts..."

[jocko]

Interested in picking a few of your brains on the subj of 5-speeds. My question is specific to the TKO500 and TKO600. Gear ratios are as follows:

TKO-500 3.27(1) 1.98(2) 1.34(3) 1.00(4) .68(5) (Rated to 500 ft/lbs)
TKO-600 2.87(1) 1.89(2) 1.28(3) 1.00(4) .64(5) (Rated to 600 ft/lbs)

My 66 C10 has a 283 and 3.73 rearend (based on my chalk on the tire and driveshaft check anyway - someone must've changed it from the 3.08 that's listed on the glovebox. It sure launches like a 3.73 and tachs out at 3500 at around 55 mph).

Anyway, I digress... Here's my MAIN concern - my first choice of the two is the TKO 500 since I surely don't need a 600 hp-capable trans in the first place (i.e. the TKO 600 - I know, I know, I don't need a 500 hp-capable trans either with my little 283, but homeboy wants a 5-speed darn it!) But with a 3.73 rear and the 3.27 1st gear in the TKO 500, my first gear ratio is an astronomical 12.2:1.... In other words, I'd probably get to all of 3 mph before it would be time to shift to 2nd. Now I don't want to buy a 5-speed and never use 1st gear. The TKO 600 has a more suitable (IMO) 1st gear of 2.87 (which is still a little steep with a 3.73 rear, but much better than a 3.27 1st gear).

So, that's my concern - now here's my question -

Is the TKO 500 (with 3.27 1st gear) and 3.73 rear end a driveable combo? Anyone driven it before? Thoughts? ( I realize it's nothing like a granny 4-speed, but I don't want a granny gear)

If it's not a good combo - is a better solution to get the TKO 600 (with the 2.87 1st gear) or to swap the rear gears down to a 3.08 or maybe a 3.23 and just use the TKO 500? (i.e. the 3.27 1st gear in the TKO 500 will help dramatically with the launch of the spindly 3.08 (related concern with this approach is that 5th gear would almost be at idle!).

Or would even the TKO 600 b better with a 3.23 or 3.55, for example?

Anyway, interested in your thoughts gents, been racking my brain and thought some of you may have had some more experience with these setups than I have. (I have considered the T-5 also, but focusing this quesiton on just the TKO 500/600).

Thanks all.
Jocko

[TwoFiftyShifter]

I think you have your gears wrong.... a 3.73 rear should run way lower than 3500RPM at 55MPH... as per this calculator, and a conservative guess that you have only 27" tires, your running about 2600rpm at 55 with 3.73s. You speedo may be way off due to a gear change, as I put you at 5.13 gears to get 3500rpm at 55.

http://www.csgnetwork.com/multirpmcalc.html

Back to the tranny, those 2 first gear numbers arent much different. These trucks came with a creeper box 4 speed, which had I think a 6.55 1st gear and was good for 10mph tach'd out, so either one of those would be fine, and in a truck, the 3.27 1st would be preferable and with a 3.73 should roll out to 30mph or so.

Still you either don't have anything close to 3.73, or your speedo is WAY off and when it is indicating 55 your doing 75....

[Heater63]

How does 20mph in first gear sound?

Are you forgetting to put the tire size in your math?
With a 28-29 inch tire, with a 3:27 first gear and 3:73 rears, at 2500 rpm you should be seeing about 23 mph. I don't think thats too low. You should see 2200 rpm at 70mph!

The T5's that were the precursor to the TKO's all had 1st gears in the 2;75 to 3;75 range, so a 3;27 first is right in the middle.

BTW, I'm not driving it yet, but thats the combo I have built, TKO500 with 3:73 out back.

Another thing, IIRC, If you have 3:73 gears, you cant just change the ring and pinion to go back to 3:08s- they used different diameter carriers if I understand that issue correctly.

[shrunken66stroker]

I have a brand new world class T-5 sitting in my garage that I was going to put in my truck and the the gears are as follows: 2.97,2.31,1.31,1,0.74 The ratio of my rear end is 3.73 and I had it coming out to 2500 rpms @ 80 mph in 5th. I haven't tested it, but that's what the calculator said when I plugged in all of that info plus my tire height, which I can't remember at the moment. I think it was 29", but not exactly sure. My build went a different way so it's collecting dust at the moment.

[TheDark1]

Hey Jocko, I have the original TKO, which I assume is the 500hp version since the TKO 600 wasn't offerd then. I'd have to look at my tech sheet to see the exact gear ratio's for first gear. I also have a 350 with 4:11 and a short 26" tire. I have no problem in first gear. It's no where near like a granny, but I don't need to touch the gas to move either. If I'm tired of shifting, I can take off in second gear as well with a little throttle. My motor is no race motor by any means. I built it in 1992 and it might make 300hp-350tq. It has an RV cam to put out the torque lower in the rpm range, but pulls well up to 5500. I had the TKO in there when I had 3.73 gears, but it was several years ago, and I don't remember much about the ranges of the gears. Now with the 4:11, I can use first gear if I want or do a wicked dead stop second gear burn out. It's the best of both worlds for me. I can go for a ride in the next day or so and record the rpm and gps mph readings if you'd like---jeff

[jocko]

TwoFiftyShifter, thanks for that website - I did mis-speak, I meant to say 65mph and I also didn't mention that I have 29.2 in tall tires (measured). I do have a 3.73. I'll chalk the rest up to wobble in my cheesy factory tach... Having said that - no doubt my speedo is off since my tires are a good bit taller than the stockers - so all that probably explains the difference. But as you picked up on, the 5 speed will solve any of those final drive ratio issues, my main question is about the 1st gear issue - and thanks for your thoughts on that - yours line up with everyone else's pretty much in that you don't really think 3.73:1 and 3.27 1st is too much of a problem.

Heater63 - THANKS - that is the calc I was looking for exactly - 3.73 rear/3.27 1st gear with 28-29" tire in 1st. (I was kinda exaggerating with the 3mph comment, I just wanted to be clear what I was trying to avoid) I agree, 23mph is just fine with me - thank you - that is exactly what I was lookin for! I do realize I'd need to swap the carrier if I changed to much lower of a ring & pinion, that's the main reason I don't want to bother with it and prefer to keep my 3.73. Glad you brought that up, I forgot to mention.

Dark1, sounds like you have approx the situation I am trying to avoid since I don't really plan on roasting my hides much - I want a first gear ratio that will act pretty much like a new stock vehicle. Your gear/tire combo is much more suited to smokin the tires than mine (26" tire with 4.11's -vs- 29" tire with 3.73's), so that really helps me get an idea of how mine will behave (i.e. a little more conservatively). Thanks very much - good comparison info!

Thanks gents, I really appreciate the help.
jocko

[777ralph]

I've got a 64 with 3.73 and 3 speed standard. First gear is 2.95. I think the tko500 3.27 first would be fine. Good snap off the line and still overdrive 5th. Here's a fun calculatorfor first gear:
http://www.keislerauto.com/speed_analyzers.php?sa=gm_5
Ralph

[jocko]

Originally Posted by 777ralph

I've got a 64 with 3.73 and 3 speed standard. First gear is 2.95. I think the tko500 3.27 first would be fine. Good snap off the line and still overdrive 5th. Here's a fun calculatorfor first gear:
http://www.keislerauto.com/speed_analyzers.php?sa=gm_5
Ralph

Thanks very much Ralph!

[chevy_mike]

When I had my '69 Camaro, I had bought an original TKO trans (which is not a TKO 500 version). By the time I got to the point of installing it the 500/600 series came out. I sold off my TKO and bought a TKO 600. The rear end had a stock 10 bolt with 2.73 gears. Way wrong gears but I had a 12 bolt I was going to put in with 3.55's but sold the car before I ever got to put that in.

As it was, with the 2.73's (and ZZ4 engine) it got off the line fairly well. Not quite as hard as a late model SS Camaro that I raced but once moving I hung right on his door until we backed off at 100 mph. With this gearing, I could do 120 mph in 3rd gear! Surprised more than a few passengers.

My take is this, I am more of a fan of a close ratio box and to me, I felt there was too big of a space between 1st and 2nd on the 500 model. Now keep in mind I was setting this car up to play on twisty roads/autocross so the tigher spacing of the 600 kept it more in the power band during shifting. For just a cruiser, the 500 gearing will be a little easier to start off the line but depending on your engine, you could lug it a little when you shift from 1st to 2nd.

In the end, either one will work and it comes down to your needs/wants. On MAJOR critical thing on either one is dialing in the bell housing, to get the required specs for centering. You have to measure this with a dial indicator and just don't bolt the bell housing on and then the trans. Almost ever issue I have hear with the Tremecs has come down to not setting up this runout correctly. I was very methodical with doing this and my worked perfect and shifted easy. I LOVED that trans and if I had the funds, I would be putting in one in my '65 instead of the AX15 setup I am going with.

Good luck!

[TheDark1]

You're right the torque capability of the TKO and the TKO-500 transmissions are different. All other aspects are essentially the same. In just my short search I have found torque ratings on the same part numbers to go up as high as 525, so take that with a grain of salt. Thought I'd throw these up for you guys to look at.

http://www.ttcautomotive.com/English/products/TKO.asp

http://www.ttcautomotive.com/English...ts/TR-3550.asp

http://www.5speedtransmissions.com/3550_tko.html

[bosephus]

I've got a TKO-600 with 3.90 gears and what little I got to drive it before tearing it apart I loved it!I wish this damn truck was done already!

[chevylookin]

So I just installed my WC T-5 from an 89 Camaro this weekend. I have great off the line speed and 2-4 are awesome. I swapped out the tailhousing when I got lucky at Pick ur Part in Wilmington LB and found a mechanical speedo. I just bought the whole tranny for $140. Still trying to find a suitable shifter that avoids hitting my bench but I mangled an old shifter for now. Also still trying to figure out a suitable tranny mount as the mount sits right above the E-brake crossmember and all that stuff on my 64 short/fleet. I will probably push back the E brake mount about 4-5 inches with some new cables and this & that.

Anyways, its a blast to drive now, nice and smooth even though there is some whining in 1-3 gears. Is that normal? I used Dex Merc ATF 2.8 quarts which I heard was the overall consensus. My real problem is (and I was warned by several) that with my stocker 230 L6 which is actually pushing probably around 150 HP right now, I CANNOT accelerate past approximately 78 mph. I hit the gas, and nothing. My final drive is .63:1 with 3:08's in the back. (Wishing I had my 3:73's when all this started, but they were grinded anyways) I am running I believe 27" tires in the back but my concern is the inability to accelerate much if any.

Would someone care to give me a quick laments description of the general theory of gearing real quick? Is my 5th gear slipping? Is it just through my gearing selection that it is physically impossible no matter how much more HP I put into this engine that the laws of mechanics will not allow this set up to go 100 mph? Not that I want to go that fast because fuel consumption is my main goal. Im taching at 2200 RPM at around 80 which is great, almost seems like the engine is idling as I tromp down the highway. But as soon as I hit a slight incline, back into 4th she goes. I heard that the stroker V8 Camaros used a 3:08 with the WC T5 back in the day sooooo....Either way, it has been a blast absorbing all the knowledge from you guys and I am happy with it either way. Definitely a better and more fun truck to drive.

[777ralph]

Your problem is simply lack of horsepower. (Low end torque, actually.) If you wind it out in 4th how fast are you going? Try really buzzing it in 4th so you shift to 5th at a HIGHER RPM. There's nothing wrong with5th gear. It can't slip. Your clutch can, though. If the clutch slipped in 5th, your rpm's would keep increasing while speed stayed the same.
You just don't have enough grunt to pull 5th at a low rpm. Report back, OK?
Ralph

[Captainfab]

With that tall 3.08 gear, and in 5th gear, your little 250 just isn't producing enough torque to accelerate. You would be better off with a 3.73 rear gear. All too many guys think they need a tall rear gear in addition to a OD trans. That combo typically doesn't work out. You need to have your engine to be in it's powerband at your typical cruise speed. It is also more efficient there.

[paul63c10]

Originally Posted by Captainfab

With that tall 3.08 gear, and in 5th gear, your little 250 just isn't producing enough torque to accelerate. You would be better off with a 3.73 rear gear. All too many guys think they need a tall rear gear in addition to a OD trans. That combo typically doesn't work out. You need to have your engine to be in it's powerband at your typical cruise speed. It is also more efficient there.

could you bolt on an OD to a th350? if so how'd that work with 4:10 gears?

[777ralph]

could you bolt on an OD to a th350? if so how'd that work with 4:10 gears?

Sure you can. Google "Gear Vendors" I never said it would be cheap. It's a .8 overdrive, so with 4.10's....you'd have a 3.28 gear.
Ralph

[jocko]

new news flash! I noticed Keisler is offering a new, improved TKO. sounds pretty nice, I've got a call into them with some questions as to a kit for 60-66 chev trucks. But either way, it could be fit into our trucks easily with some minor mods. here's the linky:
http://www.keislerauto.com/

[PORKY]

Originally Posted by bosephus

I've got a TKO-600 with 3.90 gears and what little I got to drive it before tearing it apart I loved it!I wish this damn truck was done already!

I'm also putting a tko600 in my short wide 1965. I have a 454 in front of it. What did you use for a rear crossmember?
Thanks
Frank

[Rich 5150 69]

Originally Posted by PORKY

I'm also putting a tko600 in my short wide 1965. I have a 454 in front of it. What did you use for a rear crossmember?
Thanks
Frank

Any mid eighties suburban trans crossmember will bolt right in like it was made for our trucks 64-66, you just need to drill two holes...

[PORKY]

Thanks for the help!

[PORKY]

Originally Posted by Rich 5150 69

Any mid eighties suburban trans crossmember will bolt right in like it was made for our trucks 64-66, you just need to drill two holes...

Can it be and AT crossmemeber or does it need to be from a manual?