(Air) Shocks Question

[klam07]

Hi all,

 

What brand/model air shocks to use on a 620? Im looking at Gabriel, based on a comparison video between Gabriel/Monroe and Gabriel seemed to be designed much better (Gabriel Vs. Monroe Airshocks). But, do they make them for 620's (edit: yes, but discontinued)? Rockauto doesn't seem to carry any, at least for me in Canada.. however they do have them for 720's. I also found the 720 variant on amazon which is cheaper and delivers faster.

I have 720 Leaf springs waiting, but I also have the u-bolt plate/bracket/shock mount to go along with it.. so theoretically I could use either 620 or the double eyelet 720 shocks..? Right?

 

Context:

Seems like my ideal setup for me, given what I want and what I can spend would be: 720 4x4 leafsprings, 3" lowering blocks, and __________ air shocks.

(ie: still having a traditional shock/leaf spring combo for lowered daily driving, and the ability to 'air up' but mainly stiffen the rear some when needed for hauling etc.)

 

Some users (Ron1200!) have this exact setup but it looks like with 620 shocks. Otherwise he's basically sold me on this setup.

While others (ben_upde!) have the double eyelet 720 lookin' ones.

 

tl;dr

- Will 720 shocks work in the rear if I have the appropriate bracket/mount?

- Gabriel vs. monroe (or even AC Delco?) airshocks. A: Gabriel

- Gabriel Hijackers (part number 49310)?

 

 

Thanks in advance for any and all info!

 

 

 

[Stoffregen Motorsports]

Most shock absorber companies have a length chart. You measure extended length (truck jacked up) and compressed length (truck on bump stops) and compare those numbers to the company's website (Usually there's a PDF file somewhere). For best measurements, the shocks should be removed from the truck. You can also measure the original shocks, and add or subtract for lift or drop.

 

You will also need to know the mounting style (pin/stem or bushing) and size (size of hole in bushing or size of thread on the stem).

 

Some manufacturers call it an application guide, some have called it a length chart. If you can't find this info, a call or email to the company should get you the info you need.

[klam07]

Thanks for the info! I guess I'm used to them being make/model specific these days as opposed to a buy-per-application scenario.

 

As far as I know, I think I should be able to use either mounting style because I have the 720 brackets. But looking for clarification on that.

Truck is parked away for the winter - so I wont have access to it for some months. Hopefully someone can share some experiences with these

 

[Stoffregen Motorsports]

Have you tried searching for these MFG's application guides? I just searched Gabriel Application Guide and in less than a minute I found a part number for the 620 Datsun - page 326 of their catalog - part number 49309 - available at Summit Racing  (though listed as not available) - https://www.summitracing.com/parts/gab-49309

 

Application guide - http://gabriel.com/wp-content/uploads/2018/01/2018-LV-Online-Catalog.pdf

 

The internet is a remarkable tool.

Edited November 2, 2019 by Stoffregen Motorsports

[klam07]

Admittedly I didn't look up Gabriels. I did however look into AC Delco's yesterday trying to find an application guide or catalogue of some sort but only got this. As far as what I've come across, no info/products (air shocks) for 620 and 2wd 720 rears - which is consistent for other brands I've looked for and the non-availability you linked. So thanks for verifying that 620 air shocks are more or less unobtainable.

 

Gabriel's website has no product page for 49309 (620), but does have the 49311 (720 4x4) which I mentioned in the first post, as well as 49310 (510 wagon & 2wd d21) specs. Both for different applications, but mounting codes for the top and bottom are 5/8" ID, which is the same at least for the 620 upper mount. Lower mount, in theory, wouldn't matter because I have the 720 4x4 lower mount. Again, I just want to clarify that I can use it on my 620; I want to say I've seen it done on this forum but I can't retrace the exact post - is why I'm reaching out.

 

As for lengths of 49309 vs 49311/49310.. Going off of standard lengths for regular shocks on a 620 as a baseline, I'm getting that lengths can vary between different brands, and between different product lines in the same brand by as much as an inch or more. Monroe even has variances of ~3" of extended length and 2" of stroke for the same vehicle..

So is it fair to say that exact lengths aren't too particularly crucial, especially in the case of air shocks?

The gabriel catalogue has 49309 listed at 18.52" extended, while the 49310's are the next closest (with useable mounting codes) at 20.35"..

 

In the end I guess Gabriel is my best bet (49310's if possible). Monroe doesn't seem to have anything available, and AC Delco only has the 720 4x4 air shocks which are too long.

 

So, new set of questions:

- Will 720 4x4 lower shock mounts fit a 620, allowing me to use 720 style shocks?

- Will a slightly taller shock work fine in my application..?

[Stoffregen Motorsports]

Though exact measurements may not affect the average vehicle, shock length is important on my builds.  I try to maximize the suspension travel whenever selecting a shock. The two obvious reasons I would be careful selecting a shock are A - if they are too long, they can bottom out before the axle hits the bumpstops, and B - if they are too short, they can top out before your suspension is ready to do so. In either case, that means lost suspension travel. On a super low car or truck, that comes with the turf and owners expect that, but for every day driving, I would not want that.

 

The best way to answer your question of length is to measure the suspension yourself and check that against the shock measurements. If you have some fabrication capabilities, you can take a longer shock and make it fit without compromises. Raising the upper mount or lowering the lower mount is how you achieve this.

[datzenmike]

Lowering with blocks has zero effect on shock length. Re-arching spring to raise or lower ride height will have some effect on shock lengths. If raised, the stock shock will possibly extend to it's limit on a bump and the tires leave contact with the ground. Definitely not good on a corner. Lowered with springs will likely hit the bump stops long before the shock will bottom, else why would the factory bother with them?

[klam07]

@Stoffregen Motorsports - Thanks for your input. I'm a 1/10 on fab so at least for now I'll be looking for direct bolt ons. Ill take measurements when I get blocks and eventually swap my leafs - and compare with the models mentioned.

 

@datzenmike - Thats actually a question I was wondering about - with the lowering blocks. Thanks for clarifying. Going with 720 leafs, I'd imagine would have the same effect as a slightly de-arched spring; ie: lower ride height. So, shorter bump stops, and hopefully not a notch. And with air shocks, I'd have the ability to find the 'balance' between ride height (aesthetic & functionality) and ride quality.

[datzenmike]

Raising or lowering will upset the driveshaft angles so be aware of and watch for any introduced vibration. It's adjustable so don't worry and don't put up with it.

[knoriega]

I went with 4X4 leafs, 3" lowering blocks, and order Monroe MA709 from Orieley's Auto Parts (comes with Llfe-time warranty) and about half price compared to Gabriel highjackers. I think I paid about $53. I also removed bump stop off axle. Rear rim size is 17" with 245/40/17 tire. I adjust air to ride with tire level with fender height.  The air shocks mad a Day and night difference in ridability and comfort for my ol' Ass. The Monroe MA709 were shoert enough to allow enough travel for shock to do it's thing. I think I am running air pressure around 40 # psi

[Stoffregen Motorsports]

And there's your answer. Thanks knoriega.

 

Question - with a 3" drop and the bumpstop removed, does it bottom out anywhere?

[knoriega]

It will bottom out, depend on how much travel is used. I I say I have about 2" before hitting frame. I might c-notch in future, but for know it is ok for me.  I will try and post pictures later. Or can see at Eagle Rock swap meet in So Calif this coming weekend.

[klam07]

10 hours ago, knoriega said:

I went with 4X4 leafs, 3" lowering blocks, and order Monroe MA709 from Orieley's Auto Parts (comes with Llfe-time warranty) and about half price compared to Gabriel highjackers. I think I paid about $53. I also removed bump stop off axle. Rear rim size is 17" with 245/40/17 tire. I adjust air to ride with tire level with fender height.  The air shocks mad a Day and night difference in ridability and comfort for my ol' Ass. The Monroe MA709 were shoert enough to allow enough travel for shock to do it's thing. I think I am running air pressure around 40 # psi

 

Thanks for this! Exactly what I was looking for. Interestingly the MA709 are only listed for domestic cars but I checked the mounting code/bushing ID and its 5/8" too. Its a bit cheaper than Gabriels for me, but only by a bit so Ill still consider both for now.

 

Very interested in seeing some pics of your truck in profile! Cheers

[knoriega]

Yes MA709 is what I am currently have on my truck, they are for a ford capri, but datsun 620 is basically a small car...lol. They  are a little cheaper than Gabriel, but still offer lifetime warranty. Check with your parts house an see if they have lifetime warranty in Canada. Sorry for confusion on which model number form Monroes. The correct model is MA709

[knoriega]

Actually, I changed the 3" block to a 2" block to give over 3" travel for axle. The top of rear tire sits in wheel well about 1/4". Rear driveline  lined up better too...no humming

[klam07]

Thanks for the help Knoriega!

Answered all my questions and some. Looks like everything checks out, and the Monroes seem to be the way to go.