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Fitment of new Tremec TKX

Flchallenger

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Has anyone installed one of the newer TKX 5 speeds. Did you have to enlarge the tunnel? Is it much smaller than the TKO's. I am considering installing one.
 

Bstoker87

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Got mine fit going from auto to manual using a AMD 4 speed tunnel, fits with plenty of room.

Also should mention a stock TKX will not work, I'm using a SST TKX.
 

moparlifer

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Yes, agreed.
I just ordered and received mine from SST.
They machine the case to make them fit and then pressure check it to make sure nothing leaks.
Glad to gear it fits the stock tunnel!
I'm going to test fit mine in a few weeks.
 

Flchallenger

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Well I got it in and I can't get the tail end to go any higher than the tkx. that was in it. Shifts alot better though. However it vibrates worses than the tko when just crusing at 70 mph. When you floor rattles like crazy. Can anyone recommend someone that can set this thing correctly. I have been fighting this for 15 years when I put the first tko in it. I got leaf spring rear end with cal trac ladder bars to keep the pinion from moving and changing. got a high dollar driveshaft with a cvc joint instead of a u joint. Have had probably 6 different people work on it with virtually no change. changed pinion angles to no avail. 150 k and still can't drive it.
 

Flchallenger

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I was under the impression I would be able to get the tail of this up to create a better angle for the drive shaft. Also the center link rubs on the oil pan. Finally just had a channel welded into the oiil pan to give it room.
 

Bstoker87

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My Uncles put a TKO kit in their 1970 Challenger and they had to put spacers in to lift the back of the trans to get the vibration to go away.
 

moparlifer

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My Uncles put a TKO kit in their 1970 Challenger and they had to put spacers in to lift the back of the trans to get the vibration to go away.
Sorry to hear of your issues. I read in some of the literature that the engine and tranny are supposed to be 2 degrees down from horizontal in back and the pinion angle 2 degrees down in front.
I also saw a chart somewhere that specs the center of the Crankshaft to the top of the K-frame is supposed to be 5-1/2 inchs with a gen 3 hemi likely the same with a early V-8. My K-frame and motor mounts had to be convinced they wanted to get there (to the 5-1/2 inch distance.
Also-check to ensure that you are using a V-8 k-frame-as the 6-cylinder and gen 2 hemi K-frame wont be correct.
I have my original K-frame and one i got from a swap meet and the angle of the idler arm mount is different between them. the one that is different has a welded tag that has 72 stamped in big letters.
Just saying if you don't know for absolute certain what the k-frame came off of it could be the issue with the idler arm hitting the Oil pan and maybe the driveline angle.
 

Flchallenger

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K frame is now a QA1 tubular. I had the car painted and the frame was bent some, all new fenders, inners in the rear, roof, trunk floor pan and k frame. Long story short, I put the TKO in around 12 years ago replacing a automatic. Since then vibrated, multiple drive shafts. Replace rear end with a Strange 60 with 390 gears. All new suspension. 512 stroker motor. Just replaced the clutches with a dual disc, flywheel and had them balanced together. This car was featured in hotrod magazine article on fixing unfixable problems. When I was having it painted and body work done they got a drive shaft builder for Nascar cars come in and look at it. He built a new drive shaft with a cvc joint on the end to tranny. This has helped some but not much. He supposedly looked at all the angles. So you would think it thats not the problem the angle because he says with the cvc angle not a issue. I am thinking maybe it's the rear end. It was added at the same time as the trans.
 

fasjac

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Has anyone installed one of the newer TKX 5 speeds. Did you have to enlarge the tunnel? Is it much smaller than the TKO's. I am considering installing one.
I put a TKO in my 73 Cuda in 2009, mine was already manual and did not have to modify the tunnel at all.
I thought the TKX might a bit larger but, you’ll have modify your tunnel anyway.
A great upgrade though. Good luck, mine was easy.
 

fasjac

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I was under the impression I would be able to get the tail of this up to create a better angle for the drive shaft. Also the center link rubs on the oil pan. Finally just had a channel welded into the oiil pan to give it room.
Mine is stock k-member and stock motor mounts, using a Milidon oil pan with no issues rubbing. I haven’t read every post but, dial indicating the bell housing is a must. If you did not.
 

Drivun

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Disappointed to hear thx doesn’t go higher than the TKO. Engine/tranny drop at rear prevented me from running TTI full length headers due to lost ground clearance.TTI shorties we’re better with a depth of only one head pipe vs two deep on the 4 tube. Guess I need further custom exhaust work to get lower ride height and still have speed bump clearance.
 

Flchallenger

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Have resolved some of vibration by putting air in my rear tires. Couldn't believe it. But I am running 18" low profile tires. They were down to 29lbs and caused the vibratiion. Aired up to 36lbs and smoothed out. I can be the simplest of things.
 

Sal C

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Yes, agreed.
I just ordered and received mine from SST.
They machine the case to make them fit and then pressure check it to make sure nothing leaks.
Glad to gear it fits the stock tunnel!
I'm going to test fit mine in a few weeks.

Where do they machine the case & why? I thought the TKX is supposed to clear everything? I just got mine from American Powertrain, so far everything they say is it clears.

Do you have a pic of the case where they machine it?

Thanks...
 

moparlifer

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It is in the car for the few weeks as i seriously crushed my thumb in the act of R&Ring motor and tranny about 8 times...Note to all: be carefull !! You don't want to loose anything you need!
I will take a picture next time I pull it out, likely over the Christmas holidays. My understanding is they machine some of the cooling ribs on top but I may be mistaken.
FWIW I have had a rude awakening installing mine.
It did not fit without cutting the tunnel, nor did it fit with-out cutting the floor pan and transmission crossmember (about 6" wide).
I looked like it would fit but it hit the cross-member at 5 or 6 degrees angle down vs flat horizontal.
The recommended angle down is 2 degrees down in back from flat horizontal. MOPAR website for gen 3 hemi's has chart that show the distance from the center of the crankshaft to the top of the K-member. To get the distance from crank to k-frame and 2 degrees down in back requires I added a 1.5" spacer under the transmission support. the shifter now sits about 1-1.5 inches higher than stock but still clears the dash. Phew..!
I have now cut out 3/4 of the tunnel and the crossmember and have finally got my 2 degrees down in back from horizontal.
However; the good news is when ordering the Holly tunnel replacement sheetmetal (bought the big one for the 6-speed this time as the one i bought for the TKO/TKX from holly had a round shifter hole in it (like a-body or b-body) right where i needed there to be metal and i cut it too small as well. I did find-out that they offer a patch piece for the bump-out in the tkx tranny where it hits the pass side tunnel vertical. The holly tunnel patch has a template you can see on the Holley website as to where to cut out and insert just aft of where the bellhousing and tranny mate-up on the pass side. But you will still need to raise-up the 4-speed tunnel hump about an inch. Now there is a transition between the aft end of the modified new tunnel sheetmetal to the stock 4-speed shifter hole. clearance from the transition to the front of the shifter trim-ring is only an inch.
I know i have the correct K-frame, motor mounts etc..I plan to mock it up and tack everthing in place over the holidays. Once i get the rear axle pinion angle set and get it running i will weld solid before painting / interior.
IMO-You should plan on cutting the pan and crossmember if you take the plunge in my opinion. If you get away without cutting all the better.
Good luck!
 

Bstoker87

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I just finished a TKX swap going from auto to manual.

The obvious is i had to cut the floor and put in the 4 speed panel made by AMD but the floor brace did not have to be cut, just had to use the SST transmission crossmember. Using the SST 1/4 shim to lift the back of the trans I'm within 2* and have 0 vibration atleast up to 50 so far.
 
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