3800 F-body Transmission Problems and (Hopefully) Solutions


v6buicks

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3800 F-body to TKO 600 swap R&D is officially in progress! After driving myself completely nuts with a few measurements, a TON of poorly constructed documents from other car clubs, and a little bit of actual research, I pulled the trigger on a couple parts to start swapping a GOOD manual transmission into my Camaro. I have my doubts that this is going to end up being as easy as it panned out in my head, but the goal is to do this with a very minimal amount of custom fabrication.

Here's the beginning of what is likely to be a very boring thread, but the results should be epic!
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On the way is a 2.8/3.1L F-body T5 bell housing. What's the reason for this one in particular? Let me take a deep breath....

The stock F-body 3.8 T5 uses a Ford case. That's right. Don't believe what you see online. The 4th Gen T5 is actually a completely different animal in relation to the "Camaro T5" that you read about on all the hot rod forums, Mustang pages, ect. The dead giveaway is the bolt pattern between the bell and the trans case, but other differences include a 26 spline input shaft, and hydraulic release bearing. This feeds the next question. Why not buy a Ford style TKO instead of changing out the bell then? For some reason, Tremec used a special pattern just for the Ford TKO which requires a custom bell. This is no problem for Ford guys, but we're talking about a Camaro that came with a FACTORY Ford transmission mated to a Buick V6. Good luck finding that on Quick Time's website!

SO! GM style TKO is probably our best bet. The Ford style trans to 3800 conversion HAS been done before while using a customized 94-95 S10 bell. There are a couple old and broken forum posts from a guy who was 3800 swapping Chrysler Conquest. I do not believe the car was ever finished though, so I'm still in the dark. What I do know is that the GM style TKO is meant to work with the old school Muncie bells. Lucky for me, the "GM T5" pattern is also a Muncie pattern, so I need a bell with that and the 3800 pattern on the other end.

I'm not sure who needs to hear this, but I'm putting it to rest. Call it what you want, but the 3800 is a Buick V6. There is hardly anything that remained the same about them between the "odd-fire" and the Series III, but the same could be said about a Gen 1 and Gen 5 small block Chevy, right? How should the 3800 be treated in terms of transmission swaps? Think of it as a 60 degree V6 (2.8, 3.1, 3.4, 3100, 3400, 3500, 3900) with a driver side starter motor. The bolt pattern IS the same on a 3800 and N* despite having 90 degree configurations. This is why I prefer to say "metric pattern" instead of "60 degree" It avoids confusion and know-it-alls. That being said, the 3800 may be a Buick engine and may not use the Chevy pattern, but the 3800 does NOT have a B.O.P.C pattern. That went away in the 80s and it's never been back. I doubt anybody here was confused about that, but I've seen some really funky and false stuff in my research.

This narrows all my T5 bell housing options down to only S10 2.8L or Camaro/Firebird 2.8/3.1L units. The S10 orients the transmission straight up and down like the TKO requires, but it's missing the driver side starter pocket. The 3rd Gen F-body has dual pockets. I don't know why, but I'm super stoked about it. Despite having the "canted" pattern, a straight up and down pattern is also partially drilled! Again, I have no idea why GM would have done that, but I'm extremely glad they did! Now I just need to finish drilling/tapping those so that the TKO bolts up!

There you go. That's why I wanted THIS bell.

This is not the "golden ticket" though. I still have some unknowns to clear. The big win is going to be measuring the depth and finding it to be shorter than my stock bell. The TKO input shaft is shorter than my stock '02 Camaro T5 shaft, so I'm REALLY hoping that this new bell is also shorter. I have a very positive vision though. I cannot confirm any of this, but it seems that all the T5 input shaft length differences are negligible as long as they share the same spline count. The 14 spline unit that came on older S10s were pretty darn short. The 26 spline V8 F-body shafts were longer. I have very little that proves or disproves that the 14 spline F-body input shafts are the same length as the S10, but I certainly cannot find anything that says otherwise. The worst case scenario is that this new bell is just as deep as my stock one and requires a custom pilot bushing that sticks out about a half inch. I wouldn't like it, and I'd prefer to use an actual bearing; however, it wouldn't be the end of the world. The best case scenario is that it just works, but I'm betting on needing a bell spacer plate which is sold in many different sizes from many different places.

Much much more to come!

Wish me luck!
 
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v6buicks

v6buicks

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Should done the CD009 :angrys00ls:
I'm sure they're stronger and cheaper which is a great reason to go that route. Not to mention having the extra gear would be sweet. I just don't think I have the skills or patience to mate a CD009 to a 3800 in an F-body. The TKO conversion should be dang close to bolting in and reuse a lot of stock parts. We'll see. It's gonna be a journey regardless of what happens.

I'm not even made that the estimated arrival time of my bell is two weeks away. With my engagement came a lot of other stuff I need to worry about before my shit box. Plus, I need to get serious about saving up for a daily. :oops:
 
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v6buicks

v6buicks

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It's here!
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Well dang.
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That sucks... They're the same depth.

I'm not sure how I'm going to deal with this. I have to somehow make up for 0.45" of lost input shaft length. What are people's thoughts on shaving a few thou from each end of the bell? Would I be risking the structural integrity too much by doing that? The more common thing to do is make and extended pilot bushing, but I'm hesitant on doing that. Is 0.45" too long? I guess there's only one way to find out.

I might just have to pull the T5 out of the car, space the bell housing off the trans about a 0.5", make a pilot bushing, apply some kind of paint or putty to the clutch splines, slap it back together, and immediately take it all apart again to note of the witnesses. I have no idea how long a typical "extended" bushing is, but I fear that with enough spacing the clutch may not be fully splined on the input shaft. This can greatly reduce the torque capacity of the clutch and input shaft. Even scarier is the thought of that clutch getting wobbly on the shaft, throwing the flywheel off balance, and blowing the **** up!
 
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v6buicks

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Here's a better idea that requires less work on my end.

I'm going to contact Modern Driveline and see if it's possible to order a GM style case with the Ford application input shaft. This would put me within 0.10" on the long side which is a clearance I'm okay with handling on my own. I know this sort of swap is not a possibility on T5s, but that's only because of the difference in gear ratios. Since TKOs share the same ratios whether it's for a Ford application or GM, I don't see why this wouldn't work. I guess I'll find out soon enough.
 
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v6buicks

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I got a quick reply from Modern Driveline. Instead of answering my question, they kinda diverted saying that an early V8 Camaro T-5 would be easier and hold up to my 400 ft/lbs. :rolleyes:

I tried to explain what I'm doing with this car a little bit better, but converting from a weak T-5 to another isn't gonna happen. I'll talk to some other vendors.
 

Mattstrike

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Not sure I follow what the problem is - but just put a spacer between the flywheel and the crankshaft. Push the flywheel into the bellhousing the needed 0.45", pushes the entire stackup deeper into the bellhousing. 120k psi tensile strength fasteners (socket head, button head) minimum. Maybe ARP makes a fancy 180k psi bolt that will fit.
 

Turbocharged400sbc

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you dont want to do that, remember its externally balanced, thats a helluva risk.

ext pilot is bewst option, been done for decades, and it can be verified with just a dial indicator on the bell face and a spin of the crank
 
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Yeeaahhh that spacer sounds like an okay idea, but the external balance would be sketchy. Plus, ARP doesn't even make the stock flywheel bolts. Even longer ones would be virtually unobtainable. I had to go to GM for new OE parts.

I did some more T5 research and had some more "break-throughs" via sketchy sources. Apparently 3rd-gen guys converting their V6 cars to V8s would just swap the bell and cut off a small section of the pilot shaft. This made the V6 T5 "fit". If that's ACTUALLY true and THIS ARTICLE is actually true, then a TKO conversion in my car is basically the opposite. The splines should be deep enough and the 3800 SHOULD just require a longer pilot bushing. I have 0 faith in hearsay, and crappy sources though. :LOL: I am also assuming that the 3800 and 60 degree V6 cranks have similar crank flanges. We'll see! I think the next step is to pull my T5, install 3rd gen bell, and measure from bell face to pilot bushing and bell face to engine side of the clutch hub. This will prove or disprove everything.
 
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I just got some game changing news from 3pedals.com who have been super helpful and responsive. They seem to think that the Ford T5 bolt pattern is no different from the Ford TKO pattern. They are also looking into whether the Camaro tilt is okay for the TKO. The guy I've been talking to claims to have used the same bell to run a 4th gen Camaro T5, Mustang T5, and TKO in his LS swapped Merkur. Sounds wild, but why did that 3800/Ford TKO swapped Conquest guy need to modify his 94 S10 bell so much? I'm more confused now.
 
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I'm calling bull on 3pedals. A basic search reveals that the TKO and T5 have "wide" and "narrow" patterns respectively. There is no chance of bolting any of my "narrow" bells to a TKO. I guess I'm on my own.
 
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It fits! I could even use a third gen slave with a clutch fork if I wanted. The 4th gen dust cover only bolts in to two of the five holes and leaves a big opening in the right side starter pocket. However, it's still close enough that it's worth modifying to fit.
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This was a really tough pic to snap. lol This is basically how I measured from from trans face to the clutch hub and pilot.
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To the end of the pilot bore. Don't forget to subtract the level! 9.6 - 2.2 = 7.4" I wasn't worried, but that will not be an issue.
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...and to the hub.
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7.1 - 2.2 = 4.9" I need to make sure the bearing retainer is a bit shorter than that.

Not pictured are two other measurements. One is the trans face to crank hub. The input splines cannot extend passed this point. 8.3 - 2.2 = 6.5" The second is the length of the clutch disk splines. They are 0.96". This must be completely splined by the input shaft at all times.

I have some more research to do, but I'm very hopeful!
 
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Good help is hard to find I tell ya...
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Nobody seems to want to answer any of my questions. Keep in mind that pictures of the bell installed on my engine were attached as well. I wish they would have explained how they came to this answer because I do not believe it one bit. Weak proof. \/ Notice that they even have a V6 bell bolted on there for slightlty stronger proof. lol

According to my measurements and researching conversion bells online. TKO bore holes are only a few tenths larger than the T5s. (4.68") I could fix that with hand tools. :rolleyes: I hope American Powertrain of all companies would reconsider their answer. So far, I'm not super impressed with the guys I've talked to yet. 3pedals at least admitted that they weren't sure of a question I asked, so I appreciate them the most. Everyone else seems to be on a bit of a high horse. I may just have to find a favorite supplier, purchase the trans, and cross my fingers. If it turns out to not be as easy as I hoped, I'll make it work.
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I did a big "no-no" when initially test-fitting the bell. I drove it home with the bolts. I almost needed a hammer to remove it. Once I put it back on to indicate, I hope it goes a little easier. I'll try to use a rubber mallet instead. it would suck to crack it! I guess if it doesn't end up going on smoothly by hand, I'll just have to install one offset dowel and try again. Has anybody else dial indicated a bell before? Have you had this issue?
 
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Sorry for the lack of updates. Yes, I'm about to put another toothpick in the car, but if you have stacks of cash and a north/south 3800 feel free to copy my homework.
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I know this looks like a modern version of Doc Brown's chalk board, but I'll simplify it. All I did tonight was make the final measurement (trans face to crank flange) and a bit of math. The results show that despite having a shorter input shaft in the GM TKO, you will still be fully engaged in a stock pilot bearing with only a tenth of an inch to spare. You can probably get away with this, but engagement closer to the transmission is better. Luckily Summit sells an extended pilot bearing for SBCs which spaces it out from the crank flange by 0.25". The SBC has the same crank bore size as the 3800 and the Muncie/GM T5 pilot shaft is the same diameter as TKO. This is a big win, and PROOF that a TKO 600 will bolt up to the 3800 without significant modifications. I will get into some more fancy stuff when it comes time to set-up the HTOB, but you might be able to get away with a stock 3rd gen Camaro slave in certain applications.
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I know I'm just teasing everybody at this point. I don't think there will be any real updates here until I can afford a transmission.

4/26/2021 EDIT: See post #103. The part store data bases have 3800 pilot bearing OD information listed incorrectly on several different platforms. In fact, no pilot correct sized BEARING for a 3800 is listed on any parts website I can find. Only bushings. This is a problem because Tremec requires a bushing to be used with their TKO/TKX. We are not screwed though. You can go to Amazon and order an HK1516 which is our bushing in the form of a needle bearing. I do not believe that an extended version is possible. However, as mentioned, the extra length should not be necessary.
 
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Since my last post, the TKX was released and I do believe that the TKO will be phased out once they are sold out. This in addition to the arrival of a prat which addresses this calls for an update.

I bought a UMI transmission crossmember. In my case, this is a necessity. The TKX does not incorporate the torque arm mount bosses like the TKO did. Most people could still use a stock crossmember because there are short arms available for better grip. These mount further down the tunnel where the seat belts bolt. I did not replace those channels when I redid my floor, so that mount will not work in my car. To make things more complicated, nobody makes TKX/TKO/T5 transmission crossmembers with divorced torque arm mounts. Therefore I decided to opt for the 4L60E crossmember. I knew that if it wasn't going to fit, it would be really close.
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It turns out that it's not as close of a fit as I thought. Hogging the mount holes out isn't quite going to cut it. A small extension on the front is going to be needed.
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"Dang, Jon. Maybe you should have done a little more research. The TH350 conversion mount already has an extension going that direction"

You're right. See the red oval I put on there? That's about where my hole would need to go. For some reason, the T56 and 4L60E mounts use square tube instead of round like the rest. Drilling a hole in this spot would cut into the tube and make the part flimsy. I don't know if it would even be possible to keep the drill straight. Therefore, I think I did well by getting the 4L60E part. It will be much easier to modify and reinforce.
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The T56 mount seems to mount to different bolt holes which won't even get you close to the length you need.

I'm going to reiterate for those who may be reading this as a "how-to". The stock V6 T5 crossmember will work just fine for TKOs and TKXs as long as you are able and willing to convert over to a short torque arm. I am not. The TKO will have undrilled provisions for the torque arm mount if you wish to use as many stock parts as possible.
 

Rdrnnr

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Jon I'm just curious but is the Ford t5 pattern the same as ours as in respect to how it mounts to the bell? Seems like maybe even just doing that would be a quick and easy upgrade from ours for somebody that wanted better but doesn't have the resources to do what your doing
 
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v6buicks

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Jon I'm just curious but is the Ford t5 pattern the same as ours as in respect to how it mounts to the bell? Seems like maybe even just doing that would be a quick and easy upgrade from ours for somebody that wanted better but doesn't have the resources to do what your doing
The difference in strength between a Ford and Chevy unit are negligible. I'm done with quick and easy in terms of transmissions. I've already had mine out three times, and I don't want to do it again any time soon! It's TKX or bust.
 
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v6buicks

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I was hoping the update was for TKX talk. I REALLY want one of these for my Buick.
Sorry! It's going to be a while before it hits the road. My bonus is scheduled to drop in less than a month. That will be when I ORDER the trans. From there I still need to figure something out in terms of hydraulics, shifter, and driveshaft. I've heard that these stock u-joints are pretty weak. It might be worth just getting a the whole drive shaft. Then again, the 10 bolt is gonna blow at some point too. 😭
 

Rdrnnr

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Sorry! It's going to be a while before it hits the road. My bonus is scheduled to drop in less than a month. That will be when I ORDER the trans. From there I still need to figure something out in terms of hydraulics, shifter, and driveshaft. I've heard that these stock u-joints are pretty weak. It might be worth just getting a the whole drive shaft. Then again, the 10 bolt is gonna blow at some point too.
Does yours have the two piece drive shaft in it or the solid aluminum one? Idk if there's any difference in the u joints or not but I'm definitely takin the aluminum one out of my other car soon
 
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v6buicks

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IIIRC GM did away with the two piece shaft in the later cars. Not sure what year that stopped.
 

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