The Stovebolt Site Forums The Shop Area The HiPo Shop T-5 Question

I have looked on several sites but been unable to locate the gear ratios and whether the speedometer is mechanical or electric on a 1988 T-5 from an S-10 originally behind a 2.5L 4 cylinder. Also do I need the any part of the clutch assembly to put it into a 52 Chevy with a 58-62 235 and keep the foot starter?

I cant help you alot, I do have an s-10 five speed with a blazer rear end installed in my 52 a couple of yrs ago.........mine is I believe from and 84......2.8.......I still have the foot starter, the guy that did the work so he had no problem.. a little bit on the emergency cable but worked it out.. let me check some of my old receits and see if I can find out what clutch,,etc.......I love it even though I do have a 2:73 rear gear.........works ok for me because I dont tow or do a lot of hill climbing...........Fred

go to http://www.inliners.org/ click on tech tips,choose t-5 tranny page. I believe they were changing over to electronic speedo in 1988,some manuals were still produced.You can look at the tranny to identify if it has the electric plug or the manual thread on fitting.
Hope this helps !!

An 88 S-10 behind a 2.5 L4 is geared 3.76,2.18,1.41,1:1 and .72 and as pointed out, you have to look at the speedo hookup. The mechanical will have a fitting to accept a conventional speedo cable.

If you already have the foot starter and a 6 volt starter you will need the transmission and driveshaft with front yoke. Your clutch disc will be a RCF-4201 (10")and you can use your old pressure plate if it's in good shape. A new stock throwout bearing is recommended as well as a new pilot bushing in the crank.

You might check out a couple pics in my album that will help you with the install and eliminate clutch drag.

There is a wealth of good info out there (and also some questionable) so make sure your sources have actually done the conversion and are driving the vehicle. Hope this helps.

I've read some on this site and others about the T-5 swap but I am concerned about a "light duty" trans. originally behind a 4-cylinder or small V6 being strong enough for a full size Chevy 6-cylinder pickup. Is there a good online resourse for T-5 specs, ratios, etc. What other cars/engines was it used in/with??

I don't claim to be an expert on T-5's, just a guy that did some research and installed one in my truck. T-5's were used in AMC's, Nisson's,GM's, Ford's,Isuzu's. These were Non-World-class transmissions and were equal with exception of the gear ratios. In the Camaro's and Mustang's a World Class beefed up close-ratio version was offered with a variety of ratios. However, the WC T5's had the shift tower to the rear and would have had the shifter popping up in the middle of the seat of your truck.

The primary reason the S10 T5 is so popular relates to the forward position of the shift tower. It is oriented about 6" to the rear of the stock sm420 shifter location. The popular 1st gear and overdrive ratios are from the V-6 boxes while the 4 cylinder boxes have a higher number 1st gear and higher number overdrive. The key is to mate up your T-5 ratios with your differential R&P numbers and toss in your tire diameter. I personally wanted a setup that was inexpensive, lighter than the 175 pound sm420 (T5-75 pounds), fit with little modification would let me utilize my 235's low end/low rev torque and cruise at highway speeds with good mileage as a premium.

As for durability, I've never heard of anyone tearing up a T5 behind a stock 235. Not that it isn't possible....

jthuma94
I went to the inliners link shown above and from there went to Tremec's page. Lots of cool T-5 info, ratios, etc. The tech article on inliners is pretty cool the way the guy put the tailshaft and shifter from one trans into another. Good luck.
Thanks Fla54 for the input!

Thanks guys especially Fla54. It took a month but I finally found one. Guess I will be going to pick this T-5 up.

jthuma, glad you found a T-5 and I hope it works out for you. Keep us informed. Pics!!
Fla54, great picture documentary of your truck's transformation. Which ratio/ model of T-5 did you use? The 88 S-10 2.5 L4 you mentioned above?
I have a 50 Chevy 3/4-ton with 216 and SM420. I am interested in a "highway" gear/speed by some means but also want to be able to haul and tow. Right now it will go faster than my kingpins, shocks and tires want to go, so I have some work to do. Thanks!

Frank50,

I used an 85 S10 2.8v6 T5 with a ratio of 3.76,2.18,1.41, 1:1 and a .72 overdrive. (same ratios as jthuma94's 88 box) This was coupled to a 62" wide 88 IROC-Z Australian Borg Warner posi/disc diff with 3.08 R&P and a 29" rear tire height. I realize that this setup would have my od rpm at 65mph down around 1600 but several knowlegable Bolters are running 2.73's and on flatland they aren't complaining. My initial goal was to build a truck that got better mileage than my hot rod and ran on 87 octane pump gas. The worst that can happen is that I will just spend more time in 4th gear. I'm betting that the 235 has enough low-end torque to do the job. I'm waiting on a single Holley/Weber from Tom Langdon to see if my plan has any practical merit. The saga continues....

CHEVROLET T-5 Borg Warner Hybrid Camaro V8 26 spline output shaft Transmission Ratios:
1st: 2.95 2nd: 1.94 3rd: 1.34 4th: 1 5th: 0.74

different spline count on the clutches and input shaft ... so wait till you have what you want all in one spot. tighten the pressure plate to the fylwheel w/ proper torque specs.

I don't think you'll have a problem with the t-5 pushing or pulling the weight of the AD truck. They moved around firebirds, camaros, mustangs, jeep cherokees, s-15 and astovan loaded with people without out problems. S-10's and S-15's even towed loads with t-5's, so within reason you should be okay with yours.

As far as the clutch goes, don't buy one until you've got the original sm-420 clutch in your hands and know the size and spline of your T-5 input shaft. There were a few different diameters and your's might be 9 1/8th or 10" or 11" and you won't know til you look at the old flywheel and clutch. There are a few different input shafts on the t-5s depending on what you got it out of. If its from an s-10 chances are its a 14 spline x 1" input shaft. When you look for your clutch disc the hub should match the input shaft and the diameter matches the flywheel and clutch cover. For example, "9 1/8" & 14x1"

Thanks for all the input. 14 years ago I bought a new 92 S-10 Tahoe Sport with a 2.8 and 5-speed. Sweet little pickup. I guess that truck had a T-5, right? But then I didn't know what a T-5 was. I remember it used ATF for the trans oil. Is that what all T-5's use?

There are two types of t-5s, basically.

There are the the World Class t-5 and the 'Non-World Class" (WC v. NWC)

The Non World Class is the original and has brass syncros. All the Astro-van/S-10 t-5s are Non-World Class and need gear oil. Most of these have 14 spline input shafts.

The World Class came later and has better bearings and composite syncros. The early camaro/firebird T-5s were NWC and the later ones are all WC. Most of these have 23 spline input shafts.

With Brass Syncros, gear oil. (Non-World Class)

With Composite Syncros, ATF. (World Class)

ATF will probably work in a Brass Syncro Tranny, but gear oil in a composite syncro tranny ain't a good idea. The Brass Syncro Tranny will shift a lot smoother with gear oil, and probably stand up longer too.

There are probably even odds that someone put ATF in your brass syncro tranny, and if that is the case you should use a tranny fluid flush product before swapping back to Gear Oil. ATF and Gear Oil don't mix too well and you'll get globules.

NM51 -

You might be right about the oil in the Non World Class T-5 transmissions, but I have read many times in the past that the Non World Class is to use ATF. Mine had ATF in it when I got it and I have noticed several T-5's in pictures posted on this sight showing signs of ATF being used in them. I'd like to see more on this because one of the first write ups I ever read about using T-5 trannys behind inline six's was co-authored by Tom Langdon and the point was made clearly at that time that T-5's use GM ATF.

Joe

The T-5 shop manual refers you to the Vehicle Owner Manual or Service Manual for specifics on the lubrication schedule and approved lubricant but states that "Most T5 transmission models use Dexron II automatic transmission fluid" and "Do not use gear oil in the T5 transmsision since this may damage the blocking ring material." This manual is for both WC and Standard (NWC) transmissions.

Seems like we've been down this road before but the final answer for an S10 (NWC) T5 transmission is 70w gear oil.....which I couldn't find so I (as others have) used 70-90w and have experienced no shifting problems. I think it was from the Borg/Tremec site where they cleared up the correct lubricant question.

I suggest the Tremec home page as a great resource for this. They even have the repair/service manuals online . It says most T-5's use ATF Dexron II fluid. They also are identified in the manual as WC or STD and there are serial number charts for both. Cool info!!
Am I the only one who did not know they were made in Mexico? :confused:

It first states:

Most T-5 transmission models use Dextron II automatic transmission fluid.

It than plainly states:

DO NOT USE GEAR OIL IN THE T-5 TRANSMISSION SINCE THIS MAY DAMAGE THE BLOCKING RING MATERIAL.

It also states: Do not mix different brands or types of transmission lubricant.

I don't know about you guys, but I have never planned to run gear oil in my T-5 and even though some folks here have, I have been sure since day one that Dextron II Automatic Transmision Fluid is what the designers and engineers of these transmissions say to use in their manuals. Gear oil may not hurt, but it could cause some eventual failure. It could even void a warranty if you had the transmission professionally rebuilt.

Just my thoughts....

Joe

Both of the t-5 nwc transmissions i pulled,had atf in them.

Check out:
http://www.moderndriveline.com/index.htm

"Tech alley" and then "T5 History"

They are quite adamant about which oil to use but so are some other folks. Sure is reassuring to the consumer to know that there is this much flexibility in the petroleum products we pour in our old trucks! I guess we just have to go by "if it works for you" and hope for the best.

I will deffinetly do more research on the type of fluid to use.I just got mine back from being rebuilt.I Will make sure to use the right lube.

What did your rebuilder recommend bowtietim?

I called and left a message with him to call me.I did call a general motors dealership and talked to the people in service. They told me atf is what i should use in it.I have a co-worker that has owned s10 trucks.He said every t-5 that he has ever changed the fluid in,had atf in it.I have been told that there are a few critical areas in the t-5 that the thicker gear lube will not reach.I am going with the ATF fluid.

Here's a website to check out and a quote:

"One last piece of important information. ALL World Class T-5 use ATF oil and NOT heavy gear oil or Redline MTL! All NON-World Class T-5 use 70 wt gear oil. We recommend high quality Synthetic oil as it lasts a long time and over a larger operating temperature."

"A WC T5 takes about 2.75Qts of ATF, where as NWC T5 use 2.75 Qts of 70 weight gear oil. Tremec 3550/TKO takes 3Qts of GM syncromesh only. We recommend that you change the oil in the transmission once every two years for street driving and once a year for severe driving."

http://www.moderndriveline.com/Technical_Bits/t5_history.htm


I think alot of people have heard over and over again 't-5's take atf' so they repeat it. I don't think its true though. The NWC T-5 CAN use ATF but they were designed for 70w gear oil/syncromesh.


HERE's a great step by step article with pictures on how to rebuild your t-5. Note at the beginning of the article where it says:

"Compared to NWC T5's the WC's benefit from needle bearings under the gears and tapered roller countershaft bearings for reduced friction. This change also allows the later to run considerable less viscous ATF fluid rather than heavy gear oil."

http://www.fordmuscle.com/archives/2005/12/T5Rebuild/index.php

If you still have doubts, why not drop by the local FLAPS, open a Chilton's or Haynes for a '83 s-10 and see what it says for the 5-speed lube. I havn't done it, but I'll bet it says 70w gear oil.

I use synthetic 70w syncromesh, I think its a Valvoline product

NM51 -

The only problem with the web sites you reference is that they are Ford based web sites. We are discussing T-5 transmissions from GMC vehicles. I have no idea what the difference is (duh!), but the GMC Manuals and dealers say use Dextron II ATF. I think it's pretty clear. No way will I use oil! It's Dextron II for GMC T-5's.

Joe

NM51-
Back in May you posted a link for an online T-5 manual. I read the maintance part and in that manual is says to use Dexton II and not to use any gear oil.
I have Dextron in mine and it's been running nicely.

Borg and Warner made the t-5, not GM, Ford or Chrysler. B&W sold the trannys to GM/Ford/Chrysler and others but didn't change the mechanical design for Ford or Chrysler. So, other than the bellhousing bolt pattern, number of spines on the input and output shafts, and gear ratios, there isn't any difference in the designs of the tranny's between who put them in their cars. A NWC t-5 from ford is the same as a NWC t-5 from chevy. The syncros, bearings and guts are pretty much interchangable.

I looked at the manual published by TREMEC, the people who bought Borg-Warner's t-5 design and now manufacture only World-Class T-5's under the Tremec label and makes a tidy profit selling service parts. I paid attention to the part that said "MOST t-5s use ATF. Please refer to your owner's manual..."

I also looked on the internet and talked to several tranny people before making up my mind that I belived that the NWC tranny's need gear oil and that ATF is not viscous enough for the older bearings and brass syncros.

I guess reasonble minds can disagree- I'm going with gear oil (synthetic syncromesh), you guys go with ATF. Hopefully neither of us will suffer because of it!

I'm also open to all kinds of new information. If somebody knows of a manufacturers service bulletin, from GM or Ford, AMC or Chrysler that applies to Non-World Class t-5s that says 'use ATF', please let me know!

I think they stopped making Non-world Class tranny's almost 20 years ago (1988?) and people are just used to dealing World-Class trannys that need ATF.

I came across this site http://www.vanpeltsales.com/FH_web/t5_fivespeed.htm
click on pomoforacing link.There is a little section about trans fluid.

I see more and more information in favor of using Dextron II Automatic Transmission Fluid.

I KNOW that Borg Warner made the T-5's we are using and I still see almost everyone suggesting the use of Dextron II ATF, except for the Ford guys. Why would this be and, even if you don't care why this would be, why would you still want to use gear oil after all the comments concerning the plugging of the passages by gear oil ond other negative comments? :confused:
What are we missing here? :rolleyes:

Joe

I just put one in my 55-2 out of an 85. I put ATF in it & it felt sloppy & the syncros didn,t work good. I changed to 90-140 & it fells much better.

Bowtietim-

Great article on how to rebuild the T-5, with some good tips on how to upgrade it to the later version mainshaft bearing! I skimmed through it this morning and did notice where the guy said on Page 11:

"Whatever you do, do not use gear oil in a T-5. The lubrication passages are so small on some of the components that gear oil will not flow readily and lubricate properly. You stand a chance of spalling, galling or otherwise destroying a trans if pushed to extremes. Use Dextron III or Mercon III or a synthitic ATF without friction modifiers."


Nevertheless, a few reasons I'm sticking with gear oil in my NON-w/c t-5, even though several people seem ready to vote me off the island because of it, are:

First, the manufacturer chose gear oil after extensive testing, which I'm guessing included ATF.

Second, when Borg & Warner started making world-class T-5's for camaro's etc and continued to put NWC T-5s in trucks they STILL reccomended gear oil for the NWC but ATF for the WC. I have a hard time believing that if they didn't test ATF before, when they started the WC they still didn't test it in the NWC. For one thing, from a business perspective, it would be easier if they could order tons of ATF for their factories rather than having to order both ATF and Gear Oil.

Third, I read several other threads here where people started off with ATF and switched to gear oil because the ATF seemed looser/sloppier or whinier and once they put in the gear oil everything worked better. The people making those reccomendations are not just the FORD guys, they are mainly GM guys with T-5s in their ADs.

Maybe I'm just stubborn and stupid?

If you look at the differences between the WC and Standard T-5 it seems plausible that you should use different lubricants. The WC has journals, brass synchronizers, and straight roller bearings whereas the Standard has needle bearings, fiber synchronizers, and tapered roller bearings. I still think the best bet is to consult the owner's manual for the vehicle the T-5 came out of. One important fact that I don't think anyone has posted here is to not mix lubricants. If you decide to make the swap from gear oil to ATF or vice versa flush the transmission first.

i have a hybrid T5 (camaro (gear) gutz in an S10 housing), made for me.
My rebuilder suggests :::: redline mtl

of course the other synthetic guy (amsoil) says to run his product MTF.

The guy that rebuilt my T5 (which I have yet to install) said to use 30 wt engine oil. I asked him about ATF and he said "no, just 30 wt.". So WTF? Does anyone know the approximate viscosity of ATF? Also what properties make it different from oil, (i.e. detergents etc.)?

id run what the rebuilder said if you don't want to void your warrenty.

I have a Haynes repair manual,chevrolet & gmc s-10 & s15 2wd & 4wd pickups 1982-1993.This manual says to use Dextron II or IIE ATF.

The rebuilder said to use the same.I am going to use Dextron II ATF .

We'll deffinetly have to keep in touch and post how the t-5 transmissions are doing .

i agree w/ jthuma94 about viewing the service manual the T5 came out of.


here is a pretty cool in-site...
http://www.hanlonmotorsports.com/HanlonTIC.html

I checked the Chilton s-10 manual and the Motor lube service guide, both say to use atf, exept for the '87 Camaro, which calls for gear lube. I can't explain why the '87 would be different.
I can say that I've seen what happens when you don't use the reccomended lube in a trans. We had a kid who had a '91 4x4 dually dump truck. It was equipped with tha NV4500 5 speed. This trans calls for 50 weight Castrol synthetic oil. There's even a tag on the pto cover that says this, and give the Castrol and GM part numbers for it. This guy was insistant on using 90 wt. The last I heard he was on the 4th tranny because the kept wearing out. I drove the truck once, after the 3rd trans. The syncros were so sloppy that I could slide it in to gear without using the clutch. This was at idle, stopped.
On that note, I would think if there was a "sloppy" feel to the shifting with the correct fluid, there are probly worn parts that need to be taken care of. Using heavier oil is only masking the problem. Kind of like putting 50wt in the engine to quiet noisy rod bearings. I would suggest following the manufacturer's suggestion for the original application.

I was on autozone auto parts web site.I found out they have online repair manuals you can view online.I am waiting to see a 1985 s-10 owners manual,I'm told it says atf fluid.Here is a link to autozones information.

http://www.autozone.com/servlet/UiB...900823d/80/12/a2/b8/0900823d8012a2b8.jsp