Has your early 1st gen ever blown a transmission? Can you make a KM145 "stronger"?

[Kerrigan]

The transmission shop (we're talking again ....) said these KM145 5-speeds are known to be weak. Says the input shaft bearing goes out a lot.

As I'm now on my second one, after the previous owner rebuilt the first one at 50k miles, and working on a third, I'm wondering if this is in fact or that there might be something else that is making the problem?

He also said he sees a lot of these with pitted 5th gear from them not having a grounding strap from the tranny to the frame; at some spinning speeds they actually create an electrical arc which pits out the gear. He suggested I ad one to mine which will help it if he locates a new gear and can fix it.

Has anyone found a way to make the KM 145 a stronger transmission?

[PowerRam348]

i know that you need a grounding line on the tranny as well as two or three on the motor. you said you have two tranny's, mix and match to make one. or is 5th gear blown on both tranny's. as far them being weak, i don't think that's the case. i had 225,000 HARD miles on my transmission and when i rebuilt it, it only showed signs of normal wear. but i'm thinking that if you didn't have that ground hooked up, that could be the source of your problem. most people don't realize that engines and transmissions create static electricity and need to be grounded. i have four grounds alone on my engine and two on the transmission. if you need gears you are gonna have to go to the dealership to find them. i looked at new gears for my tranny and it was almost $400.

[camoit]

Never pull a trailer in 5th gear. Bad things happen. Trust me.

[LSR Mike]

I tore up my Tranny at Bonneville in 2009 and spent $1,200 having it re-built.
I added this 1/2 inch aluminum plate to the bottom, instead of a tin pan. This has helped me, keeps the case from flexing under stress.

http://mmeierle.com/TPParts.JPG

It's a guy working out of his garage...

[LSR Mike]

Thick!

http://mmeierle.com/TP%20Front.JPG

Before

http://mmeierle.com/Xmission%20Pan.JPG


After

http://mmeierle.com/Xmission%20done.JPG

[PowerRam348]

you could get a tuff pan for the bottom of the transmission. i also know people who have taken the gears out of their transmission and had them re-cast with better alloys so they were stronger, but that is some bucks.

[Kerrigan]

That's pretty cool. For a stock motor the KM145 Style 12mm Transmission Strengthening Pan Pro would be the best one?

[Kerrigan]

Well there's the problem. I find neither the motor or the transmission has any grounding wires going to the frame!!


i know that you need a grounding line on the tranny as well as two or three on the motor. you said you have two tranny's, mix and match to make one. or is 5th gear blown on both tranny's. as far them being weak, i don't think that's the case. i had 225,000 HARD miles on my transmission and when i rebuilt it, it only showed signs of normal wear. but i'm thinking that if you didn't have that ground hooked up, that could be the source of your problem. most people don't realize that engines and transmissions create static electricity and need to be grounded. i have four grounds alone on my engine and two on the transmission. if you need gears you are gonna have to go to the dealership to find them. i looked at new gears for my tranny and it was almost $400.

[pennyman1]

Then someone replaced the ground cable from the battery wrong. It should go from battery to under the battery tray, to the frame, then to the block. There should also be at least a grounding strap from the firewall at the heat shield to the head, and one from one of the starter bolts to the frame or battery. I ran 2 gauge battery cables on both + and - and used separate cables for each connection on the negative cable. I also ran a continuity check to ensure there were no signs of resistance building up between connections. Each spring I check the connections to make sure the connections are still good. The main problem with the early km-145 trannys is the end bearing plate wears on the main input shaft, causing the shaft to start moving around and tearing things up. My 1980 did that and a good friend of mine rebuilt it and corrected that issue when he rebuilt it. The later trannys and the starquest trannys have larger shafts and bearings, but can still fall victim to this wear issue. Another way to stiffen the tranny is to find a cast tranny pan from a starquest tsi intercooled model, 89 only. However, unless you are very lucky, finding one of those is near impossible and most likely cost more than the tuff pan.

[Kerrigan]

From the negative post on the battery to the battery pan to the frame to block. All the same cable? Is it okay if the engine to frame is a seperate cable; I do have one of those I can install. Off a stock '79 D-50.
It was suggested running a grounding cable directly from the tranny to the frame as well?


Then someone replaced the ground cable from the battery wrong. It should go from battery to under the battery tray, to the frame, then to the block. There should also be at least a grounding strap from the firewall at the heat shield to the head, and one from one of the starter bolts to the frame or battery. I ran 2 gauge battery cables on both + and - and used separate cables for each connection on the negative cable. I also ran a continuity check to ensure there were no signs of resistance building up between connections. Each spring I check the connections to make sure the connections are still good. The main problem with the early km-145 trannys is the end bearing plate wears on the main input shaft, causing the shaft to start moving around and tearing things up. My 1980 did that and a good friend of mine rebuilt it and corrected that issue when he rebuilt it. The later trannys and the starquest trannys have larger shafts and bearings, but can still fall victim to this wear issue. Another way to stiffen the tranny is to find a cast tranny pan from a starquest tsi intercooled model, 89 only. However, unless you are very lucky, finding one of those is near impossible and most likely cost more than the tuff pan.

[pennyman1]

Yes to both - I make my cable out of 3 pieces of 2 gauge cable with big lugs and heat shrink over the lugs to the cable. If the frame is well grounded, then you can ground it to the frame. The best grounding system is to ground all cables to a central bus bar that then is grounded to the battery; this prevents ground loops and grounded parts being at levels not quite at 0 volts - this causes noise in the electrical system, and can blow ecus and other electronic devices. There have been many reports of cars where the only ground for the engine and tranny was through the tranny, with some cars catching fire due to the poor grounding.

[PowerRam348]

i have grounding cables that comes off both sides of my tranny to ground it and three that come from the motor to ground it as well. you will notice a difference in performance when you ground the engine.

[Kerrigan]

Sounds like having just the OEM on from engine to frame doesn't quite hack it?

[pennyman1]

No its too small and if its original, probably corroded inside the insulation. More grounds and to a common point is best.