Jump to content

720 4x4 suspension swap?


Thisolddatsun

Recommended Posts

  • 2 weeks later...
  • Replies 224
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Update on this the tag on my fender said 3:88 when I busted my rear end apart it was 3:56.9 or something close to that . So looks like someone had this issue years ago on this truck and just forgot to mention it when I bought it lol . I wasn’t able to find a 3:88 rear end but did find a 3:77.10 in the local pull a part in a 84 2 wheel drive 720 and I changed the small input shaft to my larger input shaft and it bolted right in no issues no drama . I can’t use my 4x4 function because chances are I’m still a 3:88 in front and have a feeling the few times I used it the ratio difference between the front and the rear is what caused my differential to go out . Now I know I have a mismatched set I won’t make that mistake again . 

  • Like 1
Link to comment
1 hour ago, Stoffregen Motorsports said:

Changed the input shaft? Do you mean flange? I hope so.

 

Yes, having mis-matched R&P gears front to rear can cause problems.

The piece held in by the big nut on the pinion that you tourqe down the 2 wheel drive one was a smaller diameter than the one on my 83  . I’m slowly getting a education on this truck and this site as well some super cool knowledgeable people here and years of experience with these little trucks . 

  • Like 2
Link to comment
On 3/4/2019 at 9:11 AM, Patthedog said:

The piece held in by the big nut on the pinion that you tourqe down the 2 wheel drive one was a smaller diameter than the one on my 83  . I’m slowly getting a education on this truck and this site as well some super cool knowledgeable people here and years of experience with these little trucks . 

No worries. I was just double checking.

 

It can be a steep learning curve, but keep at it. Nothing beats experience.

  • Like 1
Link to comment
On 3/4/2019 at 1:16 PM, datzenmike said:

YUP.  Around '82 the 2wd and 4wd flange splines changed. They used to be the same but then the 4x4'xs got larger. Found this out the hard way part way through a swap.

Mike is this when Nissan started using the C200 diff instead of the H190?

Edited by Charlie69
Link to comment

Not that I know of. I grabbed a 4x4 diff and put it in then realized the driveshaft would not fit. I pulled both flanges out to swap them and .... they were different. WTF Nissan??????? 

 

The C-200 was used with the Z24 (4x4) or after Oct '83? This was an '82? 4x4 I think. The newer driveshaft was larger diameter....IIRC

  • Like 1
Link to comment
1 hour ago, datzenmike said:

Not that I know of. I grabbed a 4x4 diff and put it in then realized the driveshaft would not fit. I pulled both flanges out to swap them and .... they were different. WTF Nissan??????? 

 

The C-200 was used with the Z24 (4x4) or after Oct '83? This was an '82? 4x4 I think. The newer driveshaft was larger diameter....IIRC

In my case and maybe it’s possible it was a fluke but my truck is a early 83 made in Japan 4x4 with the large yoke driveline and or flange . The truck I found my rear end replacement in was a early 84 2wd when they first started making them in Tennessee. Perhaps it’s possible the rear end used in that 84 2wd was the same pinion as used in the 2 and 4x4 trucks made in Japan maybe the splines didn’t change till late 84 in the 2wd? But all I know is I took that small flange off and my larger diameter flange and yoke went right on tooth for tooth torqued it down and I’ve got 200 miles on it already . And who knows maybe the rear end in my donor truck had been replaced at one point because the tolerances on that thing was outrageous for being 30 years old and 250,000 miles as indicated on the truck itself 

  • Like 1
Link to comment

All 2wd are H-190.

All 4wd to Oct '83 are H-190 and changed to C-200

Some when before Oct '83 the 4wd H-190 changed the differential yoke to a different spline. If anyone knows when the driveshaft increased in diameter... that would probably be then also. 

 

Like I said I had a serious problem. I ended up cutting and grinding the spline part off and welding it to the other... kind of piggy backed. It was fucked but had no choice... worked fine. 

  • Like 1
Link to comment
  • 10 months later...

I have a 5/83 Nissan 720 it has the H190 rear diff with 3.889 gears we recently came across a gutted 85 Nissan 720 with a C200 with 4:11 gears front and back is it a direct swap taking out a H190 for the c200 ? Or are there hidden issues that changed between the trucks 

  • Like 1
Link to comment

Have you had a good visual inspection of the C200? Have you compared it to your H190?

 

I am not an expert on later model Datsun/ Nissan trucks, but over the years I have developed a list of things to check.

- overall width (WMS to WMS)

- distance between spring perch centers

- spring perch location (over or under axle)

- pinion angle ( compared at the spring perch)

- brake line routing

- parking brake cable routing/location/type

- flange type and bolt pattern

- brackets (LSV, cables, brake lines, hoses, etc)

 

Someone here has to know if this is a direct swap, but if you don't get any answers, you're going to need to check these things for yourself.

  • Like 1
Link to comment

This post I made had the wrong info so I deleted it.

 

Pinion flanges on the H190 gearsets/drop outs are interchangeable, big pattern or small pattern doesn't matter, but they do not interchange with the C200, the pinion shafts are different sizes.

 

 

Edited by wayno
  • Like 1
Link to comment
1 hour ago, Stoffregen Motorsports said:

Have you had a good visual inspection of the C200? Have you compared it to your H190?

 

I am not an expert on later model Datsun/ Nissan trucks, but over the years I have developed a list of things to check.

- overall width (WMS to WMS)

- distance between spring perch centers

- spring perch location (over or under axle)

- pinion angle ( compared at the spring perch)

- brake line routing

- parking brake cable routing/location/type

- flange type and bolt pattern

- brackets (LSV, cables, brake lines, hoses, etc)

 

Someone here has to know if this is a direct swap, but if you don't get any answers, you're going to need to check these things for yourself.

They are side by side in the garage so this is doable just was curious if someone had done it before but your logic absolutely rock solid 

  • Like 2
Link to comment

I mentioned I was fuzzy on this subject, just to make sure I was right I went out and removed a pinion flange from the C200 dually axle I have and it turns out they are not the same, the shafts are different sizes and that large pinion flange I have likely came off that 1993 H190 LSD I found years ago.

 

I am going to delete what I wrote as it is wrong. the H190 pinion flange will not fit my C200 dually axle, could you edit your post you quoted me in as the info is wrong when it comes to a C200.

Edited by wayno
  • Like 2
Link to comment
On 2/22/2019 at 8:50 AM, datzenmike said:

It is strange but the first few months the 4x4s did come with 3.889s I think build dates of Jan through June '83

 

Although the Z24 was offered in Nov. in 2wd the 4x4 lagged behind slightly. July '83 on are 4.11

I’ll throw in my 2 cents . My 5/83 4WD has the 3.889 gears - which I like . I cannot say much to driveshafts , but I do know the front driveshaft i took off an 85 I had to change flanges , the rear driveshaft I did not . I ordered flanges for the Z car driveshafts that matched the yokes to fix the front DS. 

  • Like 1
Link to comment

The impression I got from my info was the beginning of the '83 model year (July or Aug) till 11'83 when the Z24 was introduced, and many other changes. Maybe also through the rest of the year then? 3.889 is a tall gear for a 4x4... is this a short wheelbase truck?

  • Like 1
Link to comment
1 hour ago, datzenmike said:

The impression I got from my info was the beginning of the '83 model year (July or Aug) till 11'83 when the Z24 was introduced, and many other changes. Maybe also through the rest of the year then? 3.889 is a tall gear for a 4x4... is this a short wheelbase truck?

If your referring to me - it’s a standard cab . I’m not an off roader type , so for me it’s the idea of having 4wd as an option, not a necessity . Don’t plan on running 31’s , so the truck is peppy enough with the right tune even with 3.9 gears . With 4 low gearing available , I would think I could do anything I would want . 

  • Like 1
Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.