Tremec TKO to Ford FE - Input Shaft

[HSSS427]

This has been bugging me for a while, so figured a picture is worth a thousand words. Below is a diagram I made trying to determine what clearance I had between the input shaft on my Tremec TKO 600 and the crank on my 427 so. I learned the hard way that an input shaft that is too long = torn up thrust bearings, pain and agony.

I now have a short shaft installed, and understood that I would not require a spacer between the tranny and Lakewood scattershield when I used this. However, when I originally installed it, I couldn't get the input shaft to seat far enough down in the pilot bearing to get the tranny butted up against the scattershield. Based on past experience I also didn't want to force it together for fear of bottoming out in the crank.

So, installed it with the 5/8" spacer and all appeared fine. Have the engine out for other reasons, but am now concerned that I'm not getting enough engagement of the input shaft into the pilot bearing.

So, assuming I have my dimensions correct, it appears there's no way to use the longer input shaft as it's longer than the total distance from tranny face to block face. I also can't use the short input shaft without the spacer as it is longer than the depth of the scattershield plus block plate, thus appearing to invalidate the idea of using a short input shaft without a spacer.

So now the thing I don't know if how far away from the block face is the bottom of the hole in the end of the crank, and how far from the block face is the surface of the crank flange. If I have this, I can tell how much engagement of the input shaft I'm getting.

I am not and engineer, but play one when I'm in the garage. Appreciate comments, observations and corrections to my diagram to help clear this up.

[Morris]

HSSS

The input shaft is 6.5" long.....

And the Pilot Bearing needs to come out of the crank about .400"inch at a larger O.D. as a step into the crank.

Remove the Adapter plate.

Morris

[Morris]

By the way ..... Nice Drawing.....

Morris

[HSSS427]

Thanks Morris! Just so I understand your comment - the pilot bearing isn't supposed to be installed deep enough in the crank so that the outer surface is parallel with the crank flange? ie the pilot bearing needs to protrude from the surface of the flange about .4" ?

I'm thinking that the pilot bearing itself is only about 1/2' wide (just guessing as I don't have one to look at) so that wouldn't provide enough seating for the bearing would it? (Note I am using a bearing, not a bronze bushing)

Also, the length of the input shaft above is based on me any my ruler measuring the shaft itself. I did not have the bearing retainer on when I measure it, so the shaft may be protruding out of the case farther than it would with the retainer torqued down. I figured the bearing and race are protruding from the transmission case about .475" (again a simple ruler measurement that's not very precise). I measured the shaft itself from the base to be 6.1875" long, thus the total distance from the tranny case on the diagram of 6.625"

Last, but not least, I'm hoping to keep the shifter in the same location so I don't have to re-cut my transmission tunnel, thus the thought of continuing to use the spacer. In order to do that, I'm now wondering if I need to take the original "long" input shaft and have the end of it cut down and machined to a custom length.

Thanks!
Scott

[Jerry Clayton]

If you are going to use the spacer you need the long shaft--take the pilot bearing out and put in a bushing

Jerry

[trularin]

Whatever you do with all this information, I can tell you without question that if you pull the pilot bearing out from its intended shoulder, you will have a vibration you will not want to live with.

Some Toploaders for FEs are about .375 " shorter at the input and the bellhousing reflects it in the distance between the face of the transmission and the back of the engine than a something like a 351W.

It looks like the spacer you have there is throwing this all in the opposite direction. If the plate is removed, I would venture to say, about a quarter of an inch of space may be between the trans and the bellhousing.

May I suggest you contact Jimi Guthrie. He has a thread in the transmission section of this forum and tell him what you are trying to do. He may have a fast and easy solution.

Just my $0.02

PS. I am removing a Short Shaft Toploader and am installing a TKO right now, I have already been through this in a convoluted way.

[CJ428CJ]

HSSS,

I'm not familiar with the TKO, but Richmond makes only one transmission for Fords and they don't use an adapter plate. Their input shaft length is 6.49 inches which is right for small blocks. For big blocks, they say you need to trim the input shaft by 0.38 inches. So, if you're not going to use the adapter plate, that would mean your input shaft should be 6.11 inches long. If you are going to use a .625 inch thick adapter plate, your input shaft would need to be 6.735 inches long. Here's a link to their dimension illustration: http://www.richmondgear.com/01pdfs/pages25-27.pdf

By the way, my pilot bushing is flush with the crank as shown in your drawing.

Bottom line is, I wouldn't hesitate to trim the input shaft to get it to the proper length.

Chris

[HSSS427]

BTW - one of the causes of my "challenge" is that the car came originally with a cast iron Ford bellhousing. Apparently, that bellhouse is deeper/wider than the Lakewood. So switching to the Lakewood is also moving the tranny toward the engine by a 1/4 - 1/2" or so.

So, bottom line is I need to determine how long the input shaft needs to be so that I can use the spacer plate and keep my shifter in the same location. Then I can take the long shaft and have it machined to that length.

[HSSS427]

Uhhhhh CJ428CJ - your link appears to point back to this thread vs where you intended it to.....

[Jimi G]

Hsss,

My name is Jimi, I sell these particular units, if you are going to use the spacer plate you will have to use the original input, the short shaft is used to take the place of the adaptor plate. With the original cast Ford bell you would not need the adaptor plate or the short shaft kit, but it is not SFI approved like the Lakewood bell. You cannot use the adaptor plate and the short shaft together, it will not work, it will space your input to far from the pilot bearing. I have sold hundreds of these units, and several to C.C. members installing them in Cobras, and they either had the short shaft installed or got the adaptor for the back of the bell. Let me know if you have anymore questions, and I will answer them as best as I can.
jimig@standardtransmission.com

Jimi G.

[CJ428CJ]

Hsss,

I fixed the link. I think the original cast Ford bellhousings are different depending on whether it's a truck bellhousing or a car bellhousing. They are slightly different but I don't recall which is deeper. I thought the cast car bellhousings matched the depth of the Lakewood.

Chris

[HSSS427]

Jimi G. - Thanks for the help. So here's the direction I'm headed on this.

1. Re-install the standard "long" input shaft. Which by my measures will then make the distance from the tranny case facing to the end of the input shaft 7.375" - the input shaft is 6.9375" from base to tip, plus additional .4375" that the bearing and race extend out from the face of the tranny.
2. Use the Lakewood scattershield and block plate, part 15210, which is 6.564" deep and add the aluminum spacer plate which is .625" thick. Thus, distance from tranny face to block is 7.189"

So, the problem here is that the input shaft will extend 7.375" from the tranny face, and the block will be only 7.189" from the tranny face. Thus the input shaft is too long, even with the spacer. So, either need a wider spacer, or a shorter input shaft.

And, I'm not exactly sure how much wider the plate, or shorter the shaft, should be as I don't know how far away from the block face the bottom of the pilot hole on the crank is.

Is this making sense to anyone?
Thanks!
Scott

[Jimi G]

HSSS,

You might want to recheck your measurements, the input shaft will not extend into your crank, when you added everything up, did you account for the thickness of the bell? I personally have installed this unit in a Lonestar Classics Cobra with a FE block, and it worked fine. I worked for LSC for over a year and we did several installs there, all utilizing the short shaft.

Jimi G.

[HSSS427]

Jimi - The measurement for the bell depth including block plate is from the Lakewood web site and is what they list under part #15210. Engine is off at the shop with the bell, so don't have it to measure by hand. I do have the TK 600 and the 2 different input shafts, which I measured by hand.

[Monster]

You might want to talk to Bruce Couture http://www.moderndriveline.com/

He is a "Five/Six Speed Conversion Specialists" I had him machine the input shaft on my TKO works, great no adapters or special pilot bushing.

good luck,
Mike

[HSSS427]

OK -went out and put the bearing retainer on and measured again, and the short shaft is 6.5" long when measured from the face of the transmission. If the Lakewood measurements are right, then that would but the end of the input shaft .064" away from the block face. I'm thinking the crank shaft sticks out further than that, but not sure. If the bottom of the hole in the crank is actually below the block surface, then I should be fine with the short shaft, if I don't use the spacer. However, I then have to modify the tunnel to move the shifter forward about 3/4" from where it originally was - that's what I want to avoid as it means re-carpeting the tunnel.

[HSSS427]

OK - I re-did my drawing to now show the set-up if I use the standard length input shaft, and a spacer. This would keep my shifter in the stock location. However, this shaft is a bit too long, or the adapter plate a bit too thin to make it work. So, where can I get an adapter plate that is thicker than the 5/8" one I have? Or should I have the input shaft machined to be shorter?

Jimi or anyone else, I did a quick web search but didn't land on any adapter plates that seem to fit the bill. Any suggestions on where I can get one that fits this application?

[HSSS427]

My problem with this set-up is that it moves the shifter forward on the transmission tunnel and I don't want to re-carpet and re-locate the shifter hole, especially if I can fix the situation with using an adapter plate.

[PaulProe]

I too, am working on this problem. I spoke to Tremec tech support on Tues. morn. They told me they (Tremec) offer the short shaft kit (part no. TCKT 5729) but they do not install it as an option, nor do they have a transmission with it already installed. They rely on their distribution network to do that.

The also confirmed the 5/8" spacer plate as the alternative.

I have been looking for a picture of the spacer plate. I assume it is bored to match the OD of the input shaft collar, just like the bellhousing does. But does it have a lip on the face of it that slips into the bell housing or do you just rely on the bolts? Pictures are worth a thousand words.

I've been all over Lakewood's and McLeod's site but can't find any info on the spacers.

Thanks

Paul

[HSSS427]

Paul,
I have the plate and when I get a chance will try to post a pic for you. The one I have has a lip around the hole that the input shaft and bearing retainer stick through which indexes on the round opening in the bellhousing. As such, it aligns the plate opening with the bellhouse opening and it doesn't just rely on the bolts for alignment, but obviously it all has to line up or you can't bolt it together.

The spacer I have was on the car when I got it, so don't know where it came from. I did see adapters in a McLeod catalog online - you may want to search for "adapter plate" on the McLeod site.