The Stovebolt Site Forums The Shop Area Driveline T-5 in my 3600

Hi All, So I'm trying to determine if a T-5 will work. My worries center around the driveshaft it being Sooo long.

Also Please help me understand " . . . you need to match the 5th gear to your rear differential gear or it may be a waste of time and money"

I find this on Lugnuts web sight 4.10 or 4.11 rear diff with a V8 T5 with a 0.63 overdrive Now I have a 4.10 differential. But it not listed under Straight 6s

Good gear combinations for an inline 6 engine
(listed in order of preference)
3.73 rear diff with 0.72, 0.73 or 0.76 overdrive
3.90 rear diff with 0.72, 0.73 or 0.76 overdrive
3.07 or 3.08 rear diff with 0.86 overdrive
3.42 rear diff with 0.76 or 0.86 overdrive
3.55 rear diff with 0.76 or 0.86 overdrive

Good gear combinations for a V8 engine
(listed in order of preference)
3.73 rear diff with 0.72, 0.73 or 0.76 overdrive
3.90 rear diff with 0.72, 0.73, 0.76 or 0.63 overdrive
4.10 or 4.11 rear diff with a V8 T5 with a 0.63 overdrive
3.07 or 3.08 rear diff with 0.86 overdrive
3.42 rear diff with 0.76 or 0.86 overdrive
3.55 rear diff with 0.76 or 0.86 overdrive

So is this possible?

I put a T5 in my 3600 with a .72 overdrive.

I also changed out the rear axle for a better ratio. My single driveshaft that I had made was not too long, according to a very reputable driveshaft building company here in Norcal. Before I gave them the measurements, they told me that they would refuse to make me a driveshaft if it was too long. I believe it came in about 2.5 inches under the max. It also had to be a 4.0" diameter.

I chose a rear end with 3.73 gearing. I haven't driven it yet, but that was where the math took me with the 27" tire height that I wanted. A couple others here have 3600's who have done the same thing.

I see you have good taste in English cars too

I have a T-5 with .72 5th gear behind a '53 235 with a 4.64 to 1 rear end gears, with 28" tires. I can pull a stump in first gear and drag it down the road at 65 MPH without even knowing that its back there (except for all of the honking and police sirens).
I would like to have 30" tires on it to raise my final speed up to 70 MPH, but .63 is not necessary in my opinion.
With your 4.10 gears and inline 6, you will be very pleased with the .72 rear gears. Those transmissions are much easier to find. Mine came out of an '85 S10 which has a 4 cylinder in it.

Dito 52Carl. My 51, 3600 has 4.10s with a .72 5th gear wct5. The driveshaft shop had no problems making a 4"dia 1 piece driveshaft.

The gear ratios work out great for my needs, on flat ground I run 5th, in the hills not so much but that's what the other 4 gears are for.

Good Luck,

RonR

Great info Guy's but what does it mean and what are the Physics behind this "you need to match the 5th gear to your rear differential gear or it may be a waste of time and money"


I do Love British Sports Cars.

its not really a physics issue it is a drivability issue. All it means is if you have a low rear gear (high numerically) you can pair it with more aggressive overdrive. in other words it doesn't make sense to start with "highway gears" and then pair it with an aggressive overdrive. most of those pairings arrive at a final drive ratio in the high 2.xx:1 range and that is the point.

Great, Thanks Tom!

It's all about the math. Tire size matters. Most trucks with a T5 have a 28" or 29" diameter tire. Multiply the tranny gear X the rear gear. When choosing overdrive, getting the final number between 2.6 and 2.8 will make you smile the most. Having 1st gear X rear diff between 9 and 12 will make it feel good off the line without having to shift too quickly.

Only the V8 Camaro/Firebird T5s have the 0.63 overdrive. They also have a 2.95 first gear.
So your 4.10 rear combined with either a 3.75 or 4.03 first gear (found in T5s from V6 Camaros and S10 trucks) will make first gear seem like a granny gear. 4.10 X 3.75 = 15.375. Worse if the first gear is 4.03.
I will let you do the math for the V8 Camaro T5. It has 2.95 for 1st gear and 0.63 for 5th and is a close ratio tranny. Except the drop from 4th gear to 5th is a HUGE 37%.

Great, Thanks Lugnutz,

Now I can find what I want. Thanks SOoo much!! Now I understand!

I think the 0.72 overdrive will work fine and you'd be happy. Moparguy has that comb and is happy. You would be too. First gear will feel very low.
I rebuilt a T5 for a guy with a 55 Chevy coupe. He lives in Ohio and it's flat there. We decided he'd be happy with a V8 Camaro T5 with the 2.95 first gear and the 0.63 overdrive. He had a mild 350ci engine. He loves it. He also has plenty of HP with the 350 to pull that 0.63 overdrive gear.
I mention this because before I shipped that T5 to him, I decided to give it a test run in my 1965 C10. My C10 has a stock 230ci and a 3.73 rear diff. I have a T5 from a 1983 V8 Camaro in my 65 but my T5 has the 0.72 overdrive gear. As I suspected, my inline 230 didn't like the 0.63 gear on hills. It would slow down and then start to lug the engine. Whereas my 0.72 overdrive gear does fine in the same situation. If you happen to find an early V8 Camaro T5 with a 0.72 overdrive, then grab it. It has all the gears you would want for excellent driving with your 4.10 diff.

SO, I'm looking at a T-5 with a cable driven speedo. The Gear's are not correct. Can I swap the gears at a transmission shop?

What vehicle did the T5 come out of?
The 1988 and earlier S10 T5 will have a cable connection. Very hard to find. Grab it if the price is reasonable. The case and tail housing alone are worth $250 all day long.
The Camaro T5 has a cable speedo connection up through 1992 (and beyond) but 1992 is the last year the Camaro T5 had a Muncie pattern case.
Anyway, if you have found a Camaro T5, it may have the cable to VSS converter. No big deal. It has the drive gear inside the tail housing.

Different speedo gears are available- they come in different colors coded to their number of teeth. Just be sure you order the gears for a GM T5- the speedo gears from the Ford version will NOT mesh properly. Speedo gear for GM T5

If I remember correctly, the "Driven" gear is the same as (or at least will interchange with) a TH350 trans.

Ooops! I misunderstood your "gears" question. The drive gear inside the T5 will have either 9 teeth (red) or 7 teeth (blue). Those are the only colors available for the drive gear. You may need to change to the other color based on what driven gear you can get your hands on. The correct combination can usually be ordered. You must know tire rolling diameter, rear diff gear and the number of drive gear teeth to calculate the driven gear teeth.

Thanks for the info on the speedo gears! The Seller says it's from a S-10. Gearing goes like this 4.03, 2.37, 1.49, 1.0, .86. These are the gears I was wanting to change. Is it possible to swap gears and have a better setup with my 4.10 rear end

He also said the drive gear is a 9 and the driven gear is a 20. Also has a 14 tooth spline input.

Sorry I write so bad. This transmission is a Non World Class . In the message above I'm talking about the speedo drive.

Sorry I write so bad. This transmission is a Non World Class . In the message above I'm talking about the speedo drive.

You need a non world class (also called "Standard") trans with mechanical speedo drive. But a .86 overdrive? Maybe not the best choice for your rear end?

Gear/rpm calculator: Gear/mph/rpm calculator

Another T5 Application List: T% Tansmission Models list

Remenber, you get the ID # off the trans only from the tag that is hanging off a bolt (or the green/white sticker). The casting numbers in the aluminum parts are meaningless in this regard- do not use them to ID a T5 transmission.

Dave I tried the "Gear mph calculator." It describes using a 4.1 rear 33 " tires .86 gear as an engine speed of 2334. That's not bad.

Yes, it is possible to change the 5th gear from 0.86 to 0.72. Don't be fooled into thinking that a 0.63 gear set or 0.72 gear set from a V8 Camaro with be the same ratio if swapped in to an S10 T5. The numbers all change because the gear teeth numbers are different. Also, you can't buy just any S10 5th gear set. Some won't work because of the tooling on the main shaft. I experienced this once when I promised my customer that I'd swap a 0.72 gear set for his 0.76. I found out that I couldn't do it because the snap ring location wasn't at the right place. He's happy with the 0.76 but would have been even happier with the 0.72. Nothing I could do about it though.

I have these websites saved as favorites on my computer. Very helpful.

RPM Calculator

Driven Gear Calculator and Tire Diameter Calculator - Both on Same Page - Skip the top paragraph section and just use the Speedometer Gear Calculator in the second paragraph and the Tire Diameter Calculator right below that.

I will also reference my own web pages for the following:

T5 Identification - What the tags and markings mean.

T5 Buyers pre-purchase checklist.

T5 input shaft swap - skip the adapter plate.

Lugnuts, How bought sense You live so close to me. And I haven't a Clue about these transmissions. And it sounds like you've done this before. That I ask you to help me with mine. After I get the transmission I'll private message you about bringing it over.

I'd be more than happy to help. No strings attached.

I had no idea that you had 33" tall tires. I don't think I've ever seen a 3600 with tires that tall. I'm surprised that you even need an overdrive gear!

Dave, You're right my tires are 30" high so with that calculated at 65 MPH my engine is turning 2567. BTW tires also hold 80psi. That wakes them an explosion waiting to happen.

Actually E rated (10 ply rated) tires are rated at 80lbs for the maximum rated load. The wife's horse trailer pulling 2015, 3/4 ton and my backhoe pulling 1 ton normally run 80 lb. The 51 3600 with e rated tires I usually run about 45 in the front and about 35 in the rear since it doesn't carry the rated load, works fine.

Thanks Moparguy, Maximum 80psi, wonder what I could run them on a empty truck. Driving along the Interstate Hwy. A tractor trailer tire exploded. Now I'm going the other way and the shock wave/noise hit me and it was loud.Tractor never slowed down. I now pass trailers with a lot more respect.

"Only the V8 Camaro/Firebird T5s have the 0.63 overdrive. They also have a 2.95 first gear.
So your 4.10 rear combined with either a 3.75 or 4.03 first gear (found in T5s from V6 Camaros and S10 trucks) will make first gear seem like a granny gear. 4.10 X 3.75 = 15.375. Worse if the first gear is 4.03.
I will let you do the math for the V8 Camaro T5. It has 2.95 for 1st gear and 0.63 for 5th and is a close ratio tranny. Except the drop from 4th gear to 5th is a HUGE 37%."


So if I find a camero/firebird with a gear going from 3.35 to .68 NWC an I take it apart and install it in my S-10 case

I think what would work best would be to swap the S10 tail housing ONTO the Camaro case.
The gear set you mention sounds more like they are from a Mustang T5.

The answer to your question is this - World Class gears must go inside a World Class case. Non-world class need to go in a non-world class case.

The S10 T5 is World Class starting in 1993. However, 1993 is the only year that the S10 has both a World Class case and a Muncie pattern where it bolts to the bell. 1994 and up are also world class but have a Ford pattern case.

The Camaro T5 is World Class from 1988 - 1992. 1993 and up Camaro T5s are also world class but have a FORD pattern case.

Find a nice Camaro or S10 T5 with gears you like and with a Muncie case. If it's a Camaro T5, just swap the tail housing to S10.

I have a 1954 Chevy 3600 that I am trying to get an S-10 T5 tranny hooked up to. I don't know it there was a big difference between the 3100 and the 3600, but it seems by measuring that I will need to lengthen the splines by about an inch. I bought a spacer from Davis Speed Equipment (thin) that is supposed to eliminate binding of the friction disc, but don't see how when the splines appear to be needing ground back an inch or so more.
According to their instructions for use of the plate, "Slide the friction disc all the way on the S10 input shaft and measure from the face of the friction disc to the face of the transmission.
(4 5/8", measurement A.)
Then measure from the bell housing mounted to the engine to the fly wheel. ( 5 3/4", measurement B.)
If measurement A is less than measurement B your good to go, if not grind the splines longer."

Am I missing something or are the descriptions of those dimensions transposed? Seems like B should be shorter than A in order to have as much clearance as the original bearing retainer had. I have not shortened anything yet.

Wes,
I drew some pictures to help clarify. The T5 usually needs a spacer if you keep the original 14 spline shaft because the splines are not cut long enough to allow proper clutch disc travel.
The spacer moves the entire T5 back further and that functionally adds a bit of extra room for the clutch disc to travel away from the flywheel.

In my drawings, distance A must be a few millimeters less than distance B. Measure distance A with the spacer plate on the T5. Or measure distance B with the spacer plate on the face of the bell. One or the other, but not both.

If A is less than B you should be able to make the clutch disc release.

If your bell has an inspection cover, then another way to check all of this is the remove the pressure plate from the flywheel and bolt the T5 and spacer plate to the bell with the clutch disc on the shaft. If you can slide the clutch disc along the shaft away from the flywheel enough to see daylight pass between the disc and flywheel, then it’s all good.

Lugnutz,
Thanks for your time and drawings. Not sure what I was reading when I measured but when I returned to the barn this morning to re-measure I realized that I read my tape wrong. Turns out that "A" was only 1/4" larger than "B", so I only need to shorten my throw out bearing retainer collar by about 1/2" and possibly ream the clutch disc splines a bit to create the space it needs to slide freely. I don't think I will need to shorten the tip of the input shaft since it only measures 1/8'' longer that the depth of the bushing bore and the thin spacer should move it out that far, but I still can shorten it if needed.
Stopped in at FLAPS Friday and picked up a complete clutch pack for an S-10 for $100, thinking I got a great deal. Turns out the pressure plate is too small, throw out bearing may not be compatible and not sure how to extract the pilot bushing to see if the one in the kit will fit. So, maybe not a bargain after all. I am sure they are tired of me buying parts only to return them a few days later. Asked them if they sold the friction disc first and they said no, only the complete kit. Looks like all I will be able to use is the friction disc, which hardly seems worth $100.
Does the original clutch lever have a retainer to hold the TO bearing? I don't find one in my salvage parts. If it had one I think the machine shop may have lost it.
Thanks for your input.

Here are some options.
I have a slightly used 14 spline clutch disc that you can have for free. Just pay postage.
NEW Clutch Disc Options
You should go with 11” if at all possible. The weight of your truck might cause the 9 + 11/16” disc to slip.
1988 Astro van with 4.3L engine clutch disc — 14 spline and 11”
Option 1: M-PACT clutch systems part # 384212 from Rock Auto
Option 2: SACHS BBD4212 from Rock Auto
1984 S10 2.8L V6 uses 9 + 11/16” 14 spline clutch disc

Wes, Lugnutz has laid out the facts of how to make your conversion. He and his site were my goto when converting my '51, 3600 to T5 sweetness.

My approach was no spacer. Shorten the input shaft to match the original SM420 shaft length. Same with the input shaft housing. Use a Dewalt angle grinder to lengthen the clutch splines in the input shaft. Then I took the input shaft to the bench grinder and removed input shaft material on the transmission side of the shaft until the clutch had sufficient travel to work without binding. I know this sounds like a recipe for input shaft failure, but keep in mind we're dealing with a less than 100 hp stock 216 engine (in my truck anyway).

Clutch disk. I'm using the '88 Astrovan 4.3 clutch. It actually measures 10.75". Stock pressure plate works fine .

New throwout bearing.

Drilled out tanny case mounting holes to .5", used stock bolts in top holes and two new bottom bolts 2" long.

That's pretty much my story. The original thread is here.

4 years and 10,000 miles and still happy with the conversion. I did swap T5's to get a better (for me anyway) ratio .72 5th gear.

Good Luck,

RonR

Thanks to both Lugnutz and moparguy, I really appreciate the input. I'm gona do some research on the bigger clutch disc, and I do appreciate your offer, Lug. I work a part time job so I'm busy until my day off (Thu.)
So, I guess I need to order a new '54 3600 throw out bearing and at you guys' suggestion a larger than 9" (14 spline) clutch disc? Just to clarify, I am not using a SMC. I'm using the machine shop rebuilt 235, bored .060 over, with a Bulldog cam, dual 2 bbl carbs, and Williamson dual headers, all purchased from Tom Langdon, and I installed an S-10 rear end. Is that enough to justify the larger clutch disc? I don't have a problem in purchasing one, just want you guys' opinion if it is warranted. I don't plan to haul anything 'cept [censored].
I have received and installed the necessary bracketry to mount A/C, P/S, alternator and water pump from a vendor in WI, along with the 2 groove harmonic balancer. Just trying to get the T5 tranny installed. I read a post about installing studs in the top holes of the bell housing, to slide the trans onto, which sounds like an awesome idea!
Lug, if I want to take you up on your offer, how can I get payment to you? Does my email address show or can we send private messages? Still a newbe and not sure how all this works.
Wes

I can send the disc and you can mail me a check or PayPal. Either way.
Make sure you have a flywheel that can take the 11” clutch package. These two pics show a rusty flywheel that only takes the 10” standard clutch package. The second pic shows one that takes the 11” clutch disc. You can see the holes are closer to the edge of the flywheel.

Looks like after measuring my original '54 3600 4 speed clutch, it measures 10", so anything over that won't work for me in this situation. Probably stay with the 9 3/16 S-10 disc unless I can locate a 10" one. Have not looked yet.
Tried my new P/S pump tonight and it appears to be metric, so probably be sending that back. Getting pretty frustrated with all the inconsistencies. Someday I'll get there...

Wes,
Have you considered doing a Jeep shaft swap? It would solve clutch disc problems and eliminate the need for the spacer plate.
JEEP shaft swap DIY.

Lug,
Thanks for the info. I watched your slide presentation but don't think I want to go to all that trouble. I will probably ending up just taking the clutch pack back to FLAPS and seeing if they can get me an original throw out bearing for my ' 54 clutch and order a S-10 clutch disc on line from some other source. Have read that lots of guys have had satisfactory results and feel I should as well. Not gonna be a daily driver, work horse or drag racer.
I do appreciate your input and expertise, thanks.
Wes

moparguy,
I got my T5 tranny mounted to the bell housing and installed in the frame after raising the cab, and all seems to work properly. I can see space between the flywheel and friction disc when actuating the clutch lever. My concern now is getting the proper drive shaft to connect to my S10 rear end. I haven't measured yet but have read of other guys doing away with the carrier bearing. What did you go with? Custom made or salvage yard part? My 54 3600 is a long bed if it makes a difference.
Wes