1975 Brutally Simple Daily Driver

So… as for my absent CJ on the trail yesterday. Things started fairly early knowing that I was on the clock before the other guys showed up at my place. Since finishing the transmission swap I’ve had a slight vibration at speed and I think it had to do with the pinion angle. Originally, I tried to keep the transmission up high and not fiddle with the rear axle. Things were… close… but I had a difference of about 4°.



I started with a set of 4° shims but they were for 2” springs. Keep in mind that I was watching the clock, so I’m not super proud of how I just cut out enough clearance for the u-bolts, but there it is. These were used to bring the pinion angle down as a proof of concept before any cutting and welding. I ripped the Jeep around the block once and instantly noticed a rotational clunk going over bumps as the u-joints were getting bound in the yokes. That’s where I got sidelined.

As for today, I made my way down to the shop to undo the shims. Maybe the rattle was coming from the transmission? I dropped the crossmember so I could lower the transmission enough to pull the top cover and everything looked good. For good measure, I added the last half a quart of fluid I had that didn’t go in through the fill hole. Everything got buttoned back up and the decision was made to lower the transmission mount to closer match the pinion angle. Cutting ensued.



There’s not much to see, but the mount got cut off, lowered a half inch, and the crossmember got notched to make room the the relocated mount. As for the angles…



… they’re still steep, but better. The pinion and transfer case output are dead on to each other. Is the vibration gone? Well… mostly?… maybe? Perhaps there’s something going on in the transfer case? The vibration is only there at speed when I let off the throttle. Maybe I need a thicker oil in the transmission and transfer case? The t-case got plain ol’ 80/90 and the transmission got some fancy Royal Purple 75/90 due to the GL-4 or GL-5 compatibility.

Anyhow… I guess I’m not any worse than I was before the weekend. Suppose I can add the shims into the front leaf packs to get a little more caster until I get around to doing a cut/turn on the inner C’s… after a YJ spring swap… and three point seat belts… and adding another fuel tank… and a front locker… and maybe a fan shroud…

 

Looks like it is time for a double cardan driveshaft and cut and weld spring perches.

 

That time of year again to put on the winter coat.





Projects for this winter are to look at the clutch as getting into 1st needs to be just right, a fan shroud, and some small odds and ends.

 

Putting the top on, my least favorite day of the year!

 

Shop day for the CJ. Ever since the NP435 swap the clutch hasn’t felt quite as sweet as it once did. I think a ton of the issues were coming from what was left of the pivot points.



The clutch side of the bell crank was equally wallered out to the point of being completely whopper-jawed. Everything felt tight on the pedal side though. Here’s where I started…



With the clutch side taken apart, I got the bell crank out to fix the pivot holes. I decided to lengthen it to have some course adjustment availability.



Then the arm got a heim joint to replace the half worn ear.




… added a super cheesy clutch stop too since I think it was over extending the clutch ears with all the slip taken out. Feels silly smooth now.

 

If you go full heim joint on your entire linkage, your clutch pedal will feel like warm buttah.

 

Question for everyone... I'm looking to update my suspension this year. For a while I was thinking about going with a YJ spring swap, but now I'm leaning towards a 2.5" BDS kit. No idea what the current height lift is on my CJ, but it’ll still be on the 33x10.5s.

The hang-up for me is the cost between the two scenarios. On one hand, I've got no problem tackling a YJ spring swap. I was looking at using a Rough Country 2.5" lift kit as a base for around $500, but I'd also need to add the cost of spring hangers and the rest of the fiddly bits along with down time for fabrication. On the other, the BDS 2.5" kit is around $800, and I could throw it on in a weekend and just be done with it.

What say others?

 

I would lean towards whatever spring you like best. The hangers, perches and shackles, bushings and hardware might add up to $200-300. I think the installation is going to be a wash. Look at WFO ot Ruffstuff for leaf spring parts, they have good stuff reasonably priced. I think you probably can't beat the BDS price though, if it's all included.

 

The answer is always YJ springs.

 

On my current setup I run custom rear 3”ish springs both front and rear. I pushed the front end forward a 1.5-2 inches. Running 33’s. I like the benefits of a longer front spring. Rides nice and flexes well on the trails. A noticeable improvement. This required some fabrication of course. I like it and works well. I guess I just wanted to do something a little different.

Quite honestly though, if I was to do it again I’d just run a YJ suspension…and I may still do that at some point. As you probably know, YJ fronts and rear springs are both close to the length of ECJ5 rears but are wider of course (2.5 vs 1.75”). The only variance between most companies specs (YJ front/rear spring, same lift height) is spring rate and a little free arch. One of the real benefits besides better ride and articulation are the options of springs out there allowing you really put it together however you want. I’d be looking at military wrapped options, and there’s several available in many free-arch / lift varieties.

 

You've ridden in mine, those are BDS 2.5"
If that doesn't convince you to goYJ I don't know what will!

 

I put BDS 1 1/2" springs on my '71 and I wasn't super happy with them as they came.

The front sat a good 1" lower than the rear on my '71 so I made some 1" longer shackles to level it out halfway, but am not really happy about having to do that.

Pre 1/2" front lift:


My second complaint was the ride quality. The jeep was still so stiff my wife didn't like riding in it. Particularly annoying was a front-to-back pitching motion. Switching to low back seats helped with that, but it still wasn't great. I pulled the third leaf out of all the springs and it's much better now. In fact, it's better than my TJ on our rough property and my wife is fine with it now. Amazingly, it didn't change the ride height at all.

Extra leaves:


With all that said, since you're not fabrication adverse, I would go with the YJ springs. It opens up a word of cheap lift and stiffness options that you just don't have with CJ springs.

 

THIS!
I went with the YJ springs and love them. Flex well and rides nice on the street.

 

I have the narrow BDS springs and im happy with the ride quality and off road flex. One suggestion is to get the better shocks in the options when ordering. They make a big difference in ride quality. Im running bilstien 5100 shocks.

 

My vote is 2.5" BDS lift kit. I have it on 2 jeeps and love it.

Did the rough country one one because of the price point, within a year the jeep lean was 1" down on drivers side. Swapped springs side to side, jeep was level for about 6 months, leaned to drivers side, down 1".

Can't comment on yj spring conversion, but people like it, so...keep us posted on how you tackle that