Biggs Posted January 12, 2015 Report Share Posted January 12, 2015 I'm fairly new to Ratsun and have yet to get 100% into rebuilding my 521. I am in the planning stage as I set up and wire my new shop. I am curious as to whether or not I should plan to upgrade the front suspension to ball joints. Coil-overs, I've leanred, are also a possibility. Overall, I have learned a great deal from this website about my truck and what is possible, but, other than in the interest of bagging, I have not found a reason to upgrade from kingpins and torsion bars as I plan to maintain the factory height in the the front. My MG's have (and had) king pin front suspensions. I rebuilt the current car and it seems to be a good suspension (lever arm shocks not included in that statement). My 944 has torsion bars in the back and, again, I have no reason to complain. In addition, I see that king pin kits are still available on eBay. So why change? Thanks! 1 Quote Link to comment
mrbigtanker Posted January 12, 2015 Report Share Posted January 12, 2015 If you are keeping it stock hight, then dont waste your time. Ball joint would be better to me only when your king pins go bad there easier to get a hold of then good king pin kits..I have done coil overs and the set up is all wrong when its lowered. I need to redo my front end. I will say the best thing about coil overs up front though is losing the torsion bars, less weight and so much easier to work under the truck. 2 Quote Link to comment
DanielC Posted January 12, 2015 Report Share Posted January 12, 2015 No. there is nothing wrong with a kingpin front suspension in good shape. You do have to grease the front suspension parts more often, and instead of 10 or 12 Zerk fittings for grease, you have 4 to 8. A kingpin front end separates the steering joint from the suspension joints. In many cases, this can be a stronger setup. 2 Quote Link to comment
mklotz70 Posted January 12, 2015 Report Share Posted January 12, 2015 Yep.....no real reason to change if you're running stock stance and stock height. The ball joints give a lot more adjustability......if you have a need for that. They don't have much caster with the kingpins, so if you lower the front and not the back, you'll lose your caster and the steering can get squirrely. Ball joints are easier to replace than kingpins.....only an advantage if you're going to put some really high miles on. Any other benefit.....smoother ride, easier steering is pretty negligible and hardly worth the effort to do the swap. But......some guys just hate kingpins!! LOL :) 1 Quote Link to comment
wayno Posted January 13, 2015 Report Share Posted January 13, 2015 I HATE rebuilding kingpins, they are so easy to screw up when putting them together, and it's hard to get them right without the proper tools. 1 Quote Link to comment
dat521gatherer Posted January 13, 2015 Report Share Posted January 13, 2015 contrary to popular belief king pins are easy to work on. Only thing is you have to take them to the machine shop to have the pins fitted/reamed to the sleeves. Also contrary to popular belief you don't have to pay $130 for a set which has been going around on the fb 521 page. If your patient and don't mind the wait for out of country orders to take the boat you can get sets for $$35-$60. 1 Quote Link to comment
wayno Posted January 13, 2015 Report Share Posted January 13, 2015 Proper tools, that is what I said, I did a set, and I got them right on the second try with the first set, I had to pull them apart and size them, what a pain in the ass that whole thing was, will never do it again, but I normally do things myself, I don't send it out unless it's a head or block, or a starter or alt that needs rebuilt, everything else I can buy at a wrecking yard, auto parts store, ebay, or I have Mike do it. :lol: contrary to popular belief king pins are easy to work on. Only thing is you have to take them to the machine shop to have the pins fitted/reamed to the sleeves. Also contrary to popular belief you don't have to pay $130 for a set which has been going around on the fb 521 page. If your patient and don't mind the wait for out of country orders to take the boat you can get sets for $$35-$60. 1 Quote Link to comment
wayno Posted January 13, 2015 Report Share Posted January 13, 2015 Oh, I forgot, I have bought all but one of my kingpin sets for under $40.00 to my door except the Nissan set I have, I can't remember what I bought that for, I got it from a member on here. Quote Link to comment
mklotz70 Posted January 13, 2015 Report Share Posted January 13, 2015 contrary to popular belief king pins are easy to work on. Only thing is you have to take them to the machine shop to have the pins fitted/reamed to the sleeves. Also contrary to popular belief you don't have to pay $130 for a set which has been going around on the fb 521 page. If your patient and don't mind the wait for out of country orders to take the boat you can get sets for $$35-$60. I'd probably say it a bit different.... they are SIMPLE to work on, but if they have not been greased properly, they can be really hard to work on. Other than the honing by the machine shop, it's all press or hammer work for the most part. The machine shop can put the bushings in for you, but to do it yourself, it's a bit more trouble. They have to go in square, positioned correctly and not damaged in the process. The vids I've got up of kingpin rebuilding so some of the worse case stuff........but it's all very simple. I've gotten all my sets on the slow boat and have paid about $35 or so for them. The guy I was getting them from said I bought the last ones he was going to be able to get. Sooner or later, supplies have to run out. :( 1 Quote Link to comment
Charlie69 Posted January 13, 2015 Report Share Posted January 13, 2015 Also contrary to popular belief you don't have to pay $130 for a set which has been going around on the fb 521 page. If your patient and don't mind the wait for out of country orders to take the boat you can get sets for $$35-$60. Another good reason not to Facebook! 1 Quote Link to comment
datzenmike Posted January 13, 2015 Report Share Posted January 13, 2015 contrary to popular belief king pins are easy to work on. Only thing is you have to take them to the machine shop to have the pins fitted/reamed to the sleeves. Also contrary to popular belief you don't have to pay $130 for a set which has been going around on the fb 521 page. If your patient and don't mind the wait for out of country orders to take the boat you can get sets for $$35-$60. Replaced two sets in the day. Never, I say again, NEVER will I ever have a king pin truck ever again. Quote Link to comment
Phixius Posted January 13, 2015 Report Share Posted January 13, 2015 Im going to be do doing a balljoint conversion on my 521. What Lower control arm is used? I have a D21 arm and a 620 arm from a balljoint truck. Quote Link to comment
wayno Posted January 14, 2015 Report Share Posted January 14, 2015 If it was this easy, everyone would do it, if you have access to a welder, and know how to weld, it can be done, but you have to do other stuff also. Im going to be do doing a balljoint conversion on my 521. What Lower control arm is used? I have a D21 arm and a 620 arm from a balljoint truck. 1 Quote Link to comment
Phixius Posted January 14, 2015 Report Share Posted January 14, 2015 ive got most everything. Beebani uca Hardbody 2" dropspindles Rotor and calipers Wilwood master Proportion valve Lca hardbody Crossbar 1 Quote Link to comment
Phixius Posted January 14, 2015 Report Share Posted January 14, 2015 620 on left. D21 on right going with the hardbody arm. Quote Link to comment
Montzzz Posted July 13 Report Share Posted July 13 On 1/13/2015 at 12:48 PM, Phixius said: Im going to be do doing a balljoint conversion on my 521. What Lower control arm is used? I have a D21 arm and a 620 arm from a balljoint truck. hi, how did the conversion go? Im having a nightmare with my kingpins and looking for options to upgrade and found your post. a bit old, hope i get an aswer Quote Link to comment
datzenmike Posted July 13 Report Share Posted July 13 If it were easy or common everyone would have done it and probably why there is no update. The biggest think with replacing the king pins is getting a place that knows how to ream the parts properly to fit the new pin. Not that common these days. Look for a '78'-79 620 short wheelbase truck and swap your 521 cab and box onto it. Comes with front disc brakes also. The '80-'82 2wd 720 frame/brakes are similar to the late 620. I did put my '78 620 cab onto an '82 720 frame... it fit. The '83-'86 720 has upgraded front disc brakes. Get something clapped out body and engine wise for cheap. Quote Link to comment
Stoffregen Motorsports Posted July 13 Report Share Posted July 13 I did this one years ago. Basically the same as a 521, but I think the frame width may be different. It is a lot of work. Quote Link to comment
banzai510(hainz) Posted July 15 Report Share Posted July 15 On 7/13/2024 at 5:59 AM, datzenmike said: The biggest think with replacing the king pins is getting a place that knows how to ream the parts properly to fit the new pin. Not that common these days. Find a Place that does old VWs and MGs all those rigs are kingpins old Ford F100s also 1 Quote Link to comment
Stoffregen Motorsports Posted July 15 Report Share Posted July 15 There is such a thing as an adjustable reamer, but they are really expensive. Most shops that do the work will have reamers fro each model, but probably not an adjustable reamer. You can buy your own reamer and try it. Here are some inexpensive adjustable reamers - https://www.mcmaster.com/products/adjustable-diameter-reamers/ Quote Link to comment
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