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Discussion Starter #1
I have a query. And before we dive into I just want to preface this query with a disclaimer:
1) The primary reason I'm asking is because I already have all these parts left over from other projects, and I'd like to get parts off the shelves and onto cars.
2) I feel like, because I have most of the parts, the cost of buying/making anything else needed will still be cheaper than getting an entire getrag setup.


THE QUESTION(s):
  1. Has anyone put a T5 transmission into a Manta A?
  2. Which T5 did you use? (I have both an s10 4cyl and a ford v8 world class sitting on the shelf)
  3. What all was needed for the process? (i.e. is anyone making adapter plates, custom trans cross members? is there a stock driveshaft part to use as a starting place? etc.)
  4. I've read a few posts of members who've installed them in GTs, but some of their hurdles seem to be specific to the GT chassis. That said, are there any watch-outs that you feel would be universal?
 

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Über Genius
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Putting a T5 into a Manta should be as easy as putting one into a GT.
You would need a little taller shifter which you have to make yourself anyhow with the GM T5. The Mustang shifter might work.
You need a new driveline made.
You need to fab a crossmember support and find a transmission mount that would work.

The Manta transmission and the GT transmission are identical as for the length and gear ratios.
I would suggest as close to 1:1 on the overdrive as possible. I have a .76 in my GT and it's a little too much. I have to be over 65 to even enjoy it. I'd rather have had it a .86

For adapters, I have one for the GM T5 but I have it rotated 4 degrees to move the transmission flat in the car. In a Manta, it would probably lean 4 degrees.

Also, it should be noted that if you switch to a T5, you lose your speedometer.
 

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Discussion Starter #3
Putting a T5 into a Manta should be as easy as putting one into a GT.
You would need a little taller shifter which you have to make yourself anyhow with the GM T5. The Mustang shifter might work.
You need a new driveline made.
You need to fab a crossmember support and find a transmission mount that would work.

The Manta transmission and the GT transmission are identical as for the length and gear ratios.
I would suggest as close to 1:1 on the overdrive as possible. I have a .76 in my GT and it's a little too much. I have to be over 65 to even enjoy it. I'd rather have had it a .86

For adapters, I have one for the GM T5 but I have it rotated 4 degrees to move the transmission flat in the car. In a Manta, it would probably lean 4 degrees.

Also, it should be noted that if you switch to a T5, you lose your speedometer.
Where did you get the adapter? Who makes it?

As for losing the speedometer, if I understand this correctly, the s10 tail housing can be made to run an old speedo cable, then it's just a matter of having one made to fit the length. The question then becomes, which tail housing to use to keep the shifter as close to its original location as possible.

I was thinking to go with the s10 tail housing since it keeps the shift turret closer to the front, and because of that is narrower in the rear which should mean no modifying the trans tunnel.
 

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Opel Key Master
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If I recall correctly, the Chevette T5 might bring the shifter in a better place for the Manta. But you need an adapter for the bellhousing, and you need a driveshaft. The S10 T5 will work, but the ratios you will want start in 1986. 1986-88 have a 3.76 first gear but have a lousy 5th gear .72. Good thing is you can swap the 5th gears out with a 25/51 tooth, to get a .86. Don’t quote me on those gears, as I have it written down at the shop. The 86-88 have a mechanical speedometer, later NWC T5 have electric speedo, but they sell aftermarket extension housings for a mechanical speedo gear, and there is a hole under the tail shaft pickup. No mods need to be made for the speedo gear on the GM T5. Use the gears out of the Opel 4speed. The Opel and T5 have a 7/8 gear housing, and the blue gear is a 20 tooth. The inner gear is a 7 tooth (This is GT). And those gears will work, the automatic and the S-10 both have a 27 spline tail shaft. So the gear will fit just like the original. I’m playing with a couple options. HRW makes the adapters. I’m looking at building a kit to be able to bolt on, working on crossmembers now, but no definite. Of course this is for a GT, but even easier for the Manta, at least the driveshaft length is more desireable than the short one in a GT
 

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Opel Key Master
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Here are the Opel and GM speedometer housings side by side. This is a Chevette one, so it has the bigger diameter driven gear. But most of these S10s should have the smaller gear, which is just like the opel one, just different length. These could be custom machined and possibly use the GM gears and get a better cup seal, but why not use what you got already?
427772

the diameter and the lock slots are the same, after even running a Chevette transmission, I realized this just a bit ago, and wonder why. Figured it would have been done, but never saw any reference to it
 

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Discussion Starter #6
Is this the adapter from HRW you're referring to?


Do I need to locate a chevette bell housing? Or is the Opel 4-speed one the same?

This is some reallllly good info on the speedo gears! And I would love to know the notes you have written down at the shop.

I bought the light weight flywheel from the group buy, the one that will take an s10 clutch and PP, so my thought is, the s10 trans should work with everything in line that I've already got, I may just need to replace the gearset in the trans itself to be more desirable.
 

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Opel Key Master
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No and no, you will need to call HRW, they make one for the world class case pattern and a NWC S-10 to Opel bell housing. You can't just find a Chevette Bellhousing and use it, you need to find an input shaft too if you use the Chevette bellhousing. Let me clear up the confusion on the differences
Chevette (pretty hard to find) T5 out of 82-86 Chevette gas model and Pontiac T1000/Arcadia
The Chevette bellhousing will bolt up to the Opel CIH block except the top two holes, but even the dowel pins work. the shifter is about 4 inches back from say a S-10 T5 location. Not desirable for a GT, but have been told works pretty good for a Manta...I have not mounted one. I have given up on the Chevette route because they are drying up, and the ones I've ordered from junk yards have been either 4 speeds or out of something else and miss-identified.
In a GT though, the automatic driveshaft and mounts work, the drive shaft nose needs to but cut about an inch to 1-1/2 and will work fine. What I would love to have is an extension housing like the Chevette with the S-10 shifter location. The S-10 is long, and it leaves a really short driveshaft, but still seems to be the best solution and keep Opel stuff. The Ford one will more than likely have the 10 spline front shaft instead of the Opel/GM 14 Spline.
Also note the Chevette Bellhousing pattern is the total oddball of the GM bellhousing group (Astro Van may be the same) It has the Ford pattern and not the GM pattern...or Muncie pattern.
So you want to use the Opel bellhousing, and rob the speedometer gear out of it.
The Chevette has the gearing I like, or close enough, but so does the 86-later S10 NWC (except 5th gear)
The S-10 WC trans will have the Ford bellhousing pattern, but HRW makes an adapter for it too, but you need a different thickness applied due to input shaft length.
It starts getting confusing when you start going to different transmission options. There isn't just an off the shelf solution...yet. Give me some time and I will have such...but not at this moment.
 

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Opel Rallier since 1977
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OP. what are you going to be doing with this car/trannie? I ask as that may impact the gear ratios that you would want to select and that will drive you to one version of the T5 or another. The low 4's 1st gear ratio is going to not be the best... just too low for a light weight car. The WC (World Class) T5's have a lot more gear sets and other upgrades available, so IMHO that is definitely the best way to go. The Ford and Camaro V8 gearsets are a lot better for performance driving. The OD gear can be tall but can be changed if it is going to be used for something other than a highway cruiser gear..
 

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Opel Key Master
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OP. what are you going to be doing with this car/trannie? I ask as that may impact the gear ratios that you would want to select and that will drive you to one version of the T5 or another. The low 4's 1st gear ratio is going to not be the best... just too low for a light weight car. The WC (World Class) T5's have a lot more gear sets and other upgrades available, so IMHO that is definitely the best way to go. The Ford and Camaro V8 gearsets are a lot better for performance driving. The OD gear can be tall but can be changed if it is going to be used for something other than a highway cruiser gear..
The S-10s have a 4.03 first gear, until you get after 1985, then it is a 3.76, still a little taller than Opel 1st gear, but same as the Chevette, and reasonably good. And if you are looking at charts, better look at a few when running the numbers on them to find the gear ratios. They are not the most accurate. I found this to be the case on the S-10s in particular. One guy simply said any T5 after 85 has the 3.76 first gear ratio. Another source says to check it actually rotating it with markers to see what it is for sure, because again, the charts were wrong.
 

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Discussion Starter #10
OP. what are you going to be doing with this car/trannie? I ask as that may impact the gear ratios that you would want to select and that will drive you to one version of the T5 or another. The low 4's 1st gear ratio is going to not be the best... just too low for a light weight car. The WC (World Class) T5's have a lot more gear sets and other upgrades available, so IMHO that is definitely the best way to go. The Ford and Camaro V8 gearsets are a lot better for performance driving. The OD gear can be tall but can be changed if it is going to be used for something other than a highway cruiser gear..

The plan with this, and usually all my cars, is vintage back road rallying. It's more like a long roadtrip on b-roads. Driven hard, but never outside the limits, with the goal of having fun but being able to bring the car home in one piece. There are usually some dirt sections, and sometimes formerly paved sections (which are way worse). I guess you could say "canyon carving" is a good base but with suspension travel and ground clearance for unpaved roads.

The thing is, I live in Southern California, and most of these take place in the SF bay area and beyond. Having done this for years with a 4 speed volvo, I'm pretty keen to put a 5 speed in that helps reduce the drone and headache on the highway transit stages.

I have no problem changing the gearset inside. I planned to do so anyway, since I believe the WC v8 trans has better gearing than the NWC s10. But the NWC s10 trans has the right input and output shafts. I planned to make one functional trans out of the two, and if I have to buy a gear or two to make it work.
 

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Discussion Starter #11
The S-10s have a 4.03 first gear, until you get after 1985, then it is a 3.76, still a little taller than Opel 1st gear, but same as the Chevette, and reasonably good. And if you are looking at charts, better look at a few when running the numbers on them to find the gear ratios. They are not the most accurate. I found this to be the case on the S-10s in particular. One guy simply said any T5 after 85 has the 3.76 first gear ratio. Another source says to check it actually rotating it with markers to see what it is for sure, because again, the charts were wrong.
Do you have the link to the charts that had the gearset info and trans identifiers?
I used to have it saved, but I can't find it anywhere now.

I want to figure out what transmissions I have (or approximately have) so I can start to build a game plan...
 

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Read this if you haven't already

 

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Opel Key Master
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I just googled them, T5 gear ratios. And yes the world class parts as far as I know are not interchangeable with NWC. The ratios I don’t think changed in the S10 between NWC And WC, but I’m not an expert when it comes to T5 differences. Now I’m sure someone maybe makes a WC front shaft with a 14 spline. eBay searches and such will reveal that
 

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Discussion Starter #14
I just googled them, T5 gear ratios. And yes the world class parts as far as I know are not interchangeable with NWC. The ratios I don’t think changed in the S10 between NWC And WC, but I’m not an expert when it comes to T5 differences. Now I’m sure someone maybe makes a WC front shaft with a 14 spline. eBay searches and such will reveal that
From what I read (I did a lot of this research when I was looking to put a t5 in my 1968 Volvo 142s) all the parts are "interchangeable" with some modifying of the case.

For the volvo world, that usually means machining down the input shaft to the appropriate length and diameter, and then swapping over the s-10 truck tail shaft. (bunch of links below if anyone's curious)

Ref 1: www.aaronreedbaker.com T5 swap
Ref 2: T5tech1
Ref 3: T5 Transmission Rebuild
Ref 4: http://falconxl0.tripod.com/Trans_swap_v3.pdf
Ref 5: T5 tailshaft swap for dummies, with pictures.


I guess my big question really comes down to the adapter plate and your experience with HWR. I suppose since you have one they already have the opel 4-speed bellhousing measurements, yea?
It would be AMAZING if I could just call them up and order it once I know which trans case I'll be using (i.e. NWC s10 t5 vs WC ford v8 t5)
 

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Opel Key Master
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Yes, read the T5 thread on the S197 mustang to see the Ford plate. It is 1-1/8” thick. But that is due to the front shaft length. And making sure it will engage with your pilot bearing. So thickness will vary. Usually for the S10 they use a 3/4 thick plate. I think it’s best to probably go with a 7/8 thick adapter. Reason is the clutch stud needs to be adjusted before it is installed. And the spec is that the stud sticks out 3/4 of an inch, so an 1/8 extra won’t hurt.
427805

this is the S10s with the ford adapter, since I have it, I just mocked up to see where the pilot would be, it needs about 1/2” more. Adapter on the opel bellhousing, and the machined pocket for the clutch
427806

Again, don’t assume WC and NWC parts are interchangeable. I know the gears are not. That’s one reason to go with a WC is gears can be bought new. Also bearings are different, syncronizers are different. So it would be assumed the main shafts are not interchangeable either.
 

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Discussion Starter #16
I've read that thread before, but I'll re-read it now to refresh my brain.
This is all good to know, especially the adapter thickness part. I wonder if it's possible to get an input shaft made in the GM spline count, since it would be really nice to keep all the clutch stuff s-10 for ease of remembering.

You make compelling arguments and it seems like WC is the way to go for the starting point.

So, my to do list should be something to the effect of:
  1. R+D WC trans I have to figure out what gears are in there,
  2. refresh transmission
  3. Take speedo gear from opel trans
  4. swap on the s-10 truck tail housing with S10 speedo gear
  5. buy mechanical speedo gear adapter
  6. buy 7/8" adapter plate
  7. figure out input shaft (if it's swappable from the s10 or if it can be made/machined)
  8. fabricate trans mount
  9. fabricate shifter
  10. measure and make driveshaft.
Anything obviously missing?
 

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Opeler
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So, Keith....which transmission are you planning to make a kit out of? You’ve alluded to it a couple times in this, I’m sure everyone is wondering
 

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Opel Key Master
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Looks like the S10 World class is still a 14 spline front input shaft, so that should be fine. So look for a 93 and later S10. Here is a part number link, several post down shows input lengths and descriptions
Hot Rods - S10 T5 Input Shaft Lengths

I am currently doing a Chevette T5, but it will be the only one I do, as I had to buy a special offset shifter to make it work. I will then be doing S-10 T5s strickly with the 5th gear changed to .86.

The Chevette bellhousing was a thought originally, but it has a longer input shaft and if you compare to the S10 with the adapter and Opel bellhousing, the Chevette bellhousing is still an 1" longer than the adapter setup. If the bellhousing and input shaft could be used instead of the adapter, I would do that...but then the S10 driveshaft would be an inch shorter than just running the S10 adapter. I've wrapped my head around this too many times coming up with combinations, but all are not the most simple. The S197 just has too many changes and nothing is quite off the shelf, like the clutch modification, and the speedometer, and the driveshaft (which it is the least of my worries).
 

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Opel Rallier since 1977
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OK OP. My T5 plans for my 'forever Manta rally car project' (LOL) are to use the Ford T5 WC products. This is simply to get the best variety of gearsets. I have not seen the same variety of gearsets for the GM WC T5 as you can for the latest generation of Ford WC T5's.

You can build a close-ratio T5 with a 2.2 or thereabouts 1st gear and a .83 5th gear if you realy want performance or other sets, like if you want a .73 5th for easier cruising. Just a word of warning from long rally expereince on the stock Opel trans.... the 1.5+ step change from 2nd to 3rd gear really stinks; it occurs right at a critical speed for rally stages and is just too much. So if you want performance, you want to get down at 1.45 or lower on the 2-3 step.

No worry on the clutch for the Ford WC setup; there are 10 spline clutches for the 2300 I4 engine that will work fine with the Opel situation.

1-1/8" thick plate is what you want for the Ford WC trans. I am not confident that 3/4" is what you want with the Chevy WC T5; it has to be a certain thickness to get the pilot bearing set in properly. I think you have better look things over closely before you go with a different thickenss and re-read the published info.
 
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