• Registration trouble? Please use the "Contact Us" link at the bottom right corner of the page and your issue will be resolved.

C101 Frame Questions

FinoCJ

FinoCJ

1970 CJ5
Staff member
Trying to understand a few aspects of the 67-73 jeepster commando frames. Certainly there is a wb/frame length change from c101 to c104 between 71 and 72. I believe in all cases, the frame is the classic 'ladder' with parallel siderails? Basically, c101 frames are pretty strong compared to CJ6 frames, but there is not much aftermarket support for the c101 in terms of lift springs, shackles etc. Jeepsterman seems to be one of the only suppliers. What I am wondering is what CJ suspension options might cross-over to the c101 frames, as those are a bit more common.

At first I was thinking the c101 to 104 change is when other suspension changes occurred, but checking out some other details, it seems like the front suspension changed between 69 and 70? Basically, from 67-69, the
the front leaf spring set-up is identical to an early cj5/6? I am pretty sure it uses same 1.75" wide leaf springs as an early CJ, but am not 100% sure the spring length is the same - or should I say the lengthwise mount spacing is the same as early CJ? I also assume it uses the same basic shackles, mounts etc as an early CJ?

But then starting around 1970, the front spring width jumps up to 2" wide, and I assume that changes what shackles and frame mounts are used? I guess In other words, you can't just use an early cj leaf spring anymore. Did the 76 and later CJs use 2" springs on the front? Wondering that could be a source of springs for a 70-73 jeepster (both 101 and 104).

At least with the rear leafs, things stay the same all through 67-73....the springs are 2.5" wide and are mounted just outboard of the frame rails. Wondering how these springs compare to the later 2.5" wide rear CJ springs?
 
I will be interested to read these responses.
My initial reply would be there's no change in the suspension C101 to C104, '71 to '72.
I'd also wonder if the '76-up springs would fit.
I had thought the 1.75" springs ended after '75 for the CJ and Jeep went to 2" width.
Part numbers probably won't help here, because the bushing design changed mid '74 and that wipes out any continuity in part numbers.
I recall the rear 44 from a C104 matches the mounts for the '76-up, making a bolt-in replacement for the Corporate axle.
Don't take any of this as gospel, but more like what questions to ask.

Sites that sell the Dayton Spring replacement springs did have some good drawings, and might provide a dimensional reference.
For example: https://www.generalspringkc.com/1976-1986-jeep-cj-front-leaf-spring-4-leaf-640-lbs-capacity/
 
Last edited:
My JC is a 70, and it has the 2" wide front springs and OE Saginaw steering. I believe this was a mid year 70 change. The front springs are also longer than a CJ, with an offset center pin and extra length toward the rear. The rear springs are 2.5 wide and really long, again with offset center pin and a lot of extra length towards the rear. The rear springs are also outboard of the frame.
My Commando rides like a Cadillac compared to the CJ5!
If you want any specific measurements or pictures let me know.
 
Last edited:
I am intrigued by the 4" lift options....I like the idea of the longer, wider springs, possibly more articulation than typical early and intermediate CJ springs. The idea would be running a cj6 body on a commando frame with 35s and still keeping it SUA? Commando frame is also fully boxed and stronger than CJ6.....I don't know, just pontificating.
colojeepguy said:
The rear springs are 2.5 wide and really long, again with offset center pin and a lot of extra length towards the rear.
Click to expand...
This could be problematic on a cj6 where there is much less rear body overhang as compared to the commando. ALthough the wb are the same (101), the location of the axles relative to other aspects of the frame might create problems....One thing I would need to know is the OAL of the frames, and distance from the rear axle position to the rear of the frame.
Total spitball....my first thought was wondering if you could flip the rear springs around and run the short end towards the rear to match the short rear overhand of the cj6, but then the wb would grow above 101, so maybe an intermediate cj6 body on a 101 commando frame? ok, enough of that, I got other more pressing things to deal with today.....
 
FinoCJ said:
...my first thought was wondering if you could flip the rear springs around and run the short end towards the rear to match the short rear overhand of the cj6, but then the wb would grow above 101
Click to expand...
I thought of doing this with the CJ5, I posted a question about doing it awhile back, and got smacked down. Something about the long ends ot the springs facing toward each other not being a good idea. Basically the concensus was "convert to YJ springs ".
 
colojeepguy said:
I thought of doing this with the CJ5, I posted a question about doing it awhile back, and got smacked down. Something about the long ends ot the springs facing toward each other not being a good idea. Basically the concensus was "convert to YJ springs ".
Click to expand...

Yeah, I think I remember a skateboard effect or spring wrap concern.
I'ld try it if I needed new springs.

If you get measurements I can plug it into the computer and see exactly how bad the axle moves with forward facing vs rear.
 
FinoCJ said:
I am intrigued by the 4" lift options....I like the idea of the longer, wider springs, possibly more articulation than typical early and intermediate CJ springs. The idea would be running a cj6 body on a commando frame with 35s and still keeping it SUA? Commando frame is also fully boxed and stronger than CJ6.....I don't know, just pontificating.

This could be problematic on a cj6 where there is much less rear body overhang as compared to the commando. ALthough the wb are the same (101), the location of the axles relative to other aspects of the frame might create problems....One thing I would need to know is the OAL of the frames, and distance from the rear axle position to the rear of the frame.
Total spitball....my first thought was wondering if you could flip the rear springs around and run the short end towards the rear to match the short rear overhand of the cj6, but then the wb would grow above 101, so maybe an intermediate cj6 body on a 101 commando frame? ok, enough of that, I got other more pressing things to deal with today.....
Click to expand...

If you're going through that effort, you might as well swich to YJ springs so you have a wide range of cheap springs to choose from for fine tuning. You can always outboard the rear ones if you want.
 
colojeepguy said:
Something about the long ends ot the springs facing toward each other not being a good idea.
Click to expand...

But that is exactly the way the Holbrooks are configured and those work. The only problematic issue I found with the Holbrooks is having the rear axle on the short end of spring nearest the shackle, lead to some interesting issues with the pinion angle over the range of travel. That wouldn't likely be a problem with a regular driveshaft.

FinoCJ said:
that requires placing and welding on new brackets.....you know, fabricating stuff - a skill I don't have
Click to expand...
Do we give awards for BS?????
 
colojeepguy said:
Commando Springs On A Cj? | ECJ5
Click to expand...
thanks - I forgot about that thread. I didn't remember the c101/104 had offset springs - when I started this thread I was kind of wondering if they might have been basically the same as the later CJ 2/2.5 wide springs. I still think there might be something to using the 1.75" wide (67-69) front springs on an ecj5? The rear hanger would need moved back, but might be the easiest way to improve the front end flex (despite what the masses seem to suggest in that thread) - no new hangers or brackets needed, leave the front in place and keep the current shackles. These days, you can buy individual springs from Jeepsterman.....But in my case for this thread, I was wondering about mounting commando springs on a commando frame - so easy in that regard - but making it work with a cj6 body and the short overhang. Oh well, what the last 3 weeks have reminded me is that living in the shop for weeks on end is not my favorite way to spend time - especially when it is fruitless, wasted effort.
 
Last edited:
I was curious, so I parked my CJ next to the Commando with the rear wheels lined up. You can see the Commando has a LOT more rear overhang. I measured from the axle centerline to the rear crossmember. On the CJ it's about 2 ft, the Commando is 3 ft! Look closely and you can see where Kaiser tacked extra length on the frame rails.20251101_152112.jpg20251101_152209.jpg
 
You must log in or register to reply here.
Back
Top