Cutoff swap

The highest stress area for the frame is behind the cab. Now a lot of people do stretch it there but that is the highest stress area.

I would recommend against just doing one rail. The correct way for you to do that splice as the other person had said is to put a 3-foot insert at least one and a half feet on either side of the splice. It is a good idea if you can put it in the middle of the crossmember although then you have to shorten the crossmember. You cannot do any framework between the axles. It must be in front of the front hanger.

The pieces that are inserted inside the frame need to be cut the ends of them on 45 degree angles. What that does is it transfers the flex of the frame so that you don't go from the frame being rigid where it's reinforced to flexing where it's not reinforced. The 45 degree angle gives you a smooth transfer so the frame can Flex properly.

That is why you do not want to do just one side.

Just a couple quick things. Some guys cut the frame on a 45 so that they have more area to weld when they splice them together. Myself I think straight up and down is fine if you have reinforcement behind it.

Also technically you can use a MIG welder to weld the frames together. If you preheat the frame somewhat for Mig you can use it but the hardened steel that is used on those Freightliner frames really should be welded with an arc welder. A36 is fine to use for the insert. And make sure that the insert is also bolted in on either side of the splice.

 

I'm not a fan of a vertical splice. Allegedly its easier to crack a vertical weld due to the stresses. Even the insert you want the ends cut at 45 degrees for better dissipation of the stress.

I've heard lots of folks swear by a < shaped splice too. Depending on the angle you could effectively double the length of the weld.

 

They also replace the whole rail, one side. Slide then out and back in.

 

Actually Freightliner does recommend that when you splice frames together it is cut on a 45 with the top and bottom of the frame cut straight.

 

I'm going to focus on your ABS question. Both trucks have WABCO ABS. Some people giving advice need to really look up information before making blanket statements of what configurations some trucks have/don't-have. At any rate, they're both outfitted with 4S4M WABCO ABS, but the '99 has ATC option.

S/N: 591143
AXLE: RDA-T40145 391 -- DP76T17NL38 -- 3.91 axle ratio
PLATE ASSY-ECU,WABCO,4S/4M
SENSOR-ABS,2000,40X16,90D,150C

S/N: A26525
AXLE: RDA-TDS404 336 -- DP250170 -- 3.36 axle ratio
ECU ASSY-PL,WAB ATC,4S4M
SENSOR-ABS,2000,40X16,90D,220C

It looks like they both utilize the same sensor type, BUT I just think the lengths are different designated by 220 and 150. One important thing to note would be the tone-ring on the hub. I cannot determine if they are the same amount of notches on the tone rings for the two different axles. But for you, there should be a 10-pin connector somewhere in the frame rail that you can disconnect the rearward ABS wiring. Or maybe you can just simply install the ABS sensor into the donor axles no problem I think.



@xsetra you'll have to help out with pictures and locations of these connectors and such. Looking up this legacy info is rather challenging.

Here is the wiring for that 10 pin connector--keep in mind you also have the two pin connector for the ATC option (CIRC 378T+/-):

 

I guess you’re referring to me. My point was he could probably use what he has and make it work. Never claimed to be an expert. Just guessing. Now I’m guessing again, that my 99 and my current 2000 have the ATC also. That’s news to me. I didn’t think that came out till later. Maybe you can tell me. Vin # F89013

 

No I believe that is my token and he is correct. However I have no way to look that up.

 

This is where you're going to have to chip in and supply pictures. The hubs are different P/N, but I don't think that would matter too much since one axle set is TDA and the other is EATON. Remember the 4S4M stands for 4 sensors 4 modulators. So only one of your tandems is going to have the ABS tone ring--the front drive possibly...? I don't think you'd need to mess with the tone rings just yet.




Oh...one thing I forgot to mention is that both tandem drive axles on the two S/N provided are both rated for 40klbs. This is important so that nothing is underspec'd making any sort of part swap. Also the '95 is 275/80-R22.5 drive tires. and the '99 is 275/80-R24.5, but I don't think that would make too much difference in anything other than preference. You'll obviously need to do some math to get your speedo correct--but that'll be later down the line.