distributorguy Posted September 23, 2016 Report Share Posted September 23, 2016 If the cups are not a tight fit in the driveshaft, the driveshaft needs to be repaired. Period. They need to be a press fit. Anything less ensures a quickly damaged u-joint. 3 Quote Link to comment
Scgreen620 Posted September 23, 2016 Author Report Share Posted September 23, 2016 As I said, check the gear oil level and color. Will do Quote Link to comment
Scgreen620 Posted September 23, 2016 Author Report Share Posted September 23, 2016 If the cups are not a tight fit in the driveshaft, the driveshaft needs to be repaired. Period. They need to be a press fit. Anything less ensures a quickly damaged u-joint. Yes sir! Quote Link to comment
datzenmike Posted September 24, 2016 Report Share Posted September 24, 2016 The '78 620 man and auto all use a 4.375 ratio, the most common. The '79 manual has a 4.11 and the '73 automatic L16 has a 4.625 but otherwise all others are 4.375. Quote Link to comment
Scgreen620 Posted October 1, 2016 Author Report Share Posted October 1, 2016 So I went to a drive shaft repair shop they told me they had to replace the 3rd member, their basically going to cut and weld a new piece on, change all the u joints again and then balance the whole thing Quote Link to comment
G-Duax Posted October 1, 2016 Report Share Posted October 1, 2016 ??? I'm confused......but I'm getting old, so nothing new. I thought the '3rd member' is the casting that holds the diff & gears, also called the 'carrier'. Why would that need to be replaced ? Quote Link to comment
datzenmike Posted October 1, 2016 Report Share Posted October 1, 2016 I think he mentioned earlier that the U joints have failed twice in a year... probably because the yoke that holds them is damaged. If they go in less than secure they will rattle themselves to death. There was also talk about differential 'play' the rocking back and forth before there is drive force transmitted. Could be both. Hear ya on the old part though. Quote Link to comment
wayno Posted October 1, 2016 Report Share Posted October 1, 2016 So I went to a drive shaft repair shop they told me they had to replace the 3rd member, their basically going to cut and weld a new piece on, change all the u joints again and then balance the whole thing What is so great about the H190 that you have in your 620 is that there is no setting it up if you buy a good used one from someone, they are ready to be bolted in. The other thing that is great about them is that you can do the job in a few hours max, it's not that hard to do. You jack up the back of the truck and put it on stands, also block the front wheels, remove the driveline(12/13mm wrench), remove the wheels(like changing a flat), drain all the fluid out of the differential by removing the bottom drain plug(1/2 inch breaker bar) and catch the fluid in bucket, using a 10mm wrench disconnect the rear brake lines from the backing plates, you may need to catch dripping brake fluid in a container, release the park brake, remove the 4 nuts holding the backing plates on(11/16ths wrench) and pull the drum out towards you as far as possible, then do the same thing to the other side, be careful to keep the shims on the 4 studs when you pull out the axle assembly, now if the axles will not pull out more than a couple inches, you may have to loosen the e-brake cable a little, now after the differential has drained, put the drain plug back in and move the catch bucket out of your way, now with a 12mm socket remove all 10 of the nuts/lock washers holding the 3rd member in, it is very heavy so be careful not to drop it on your chest, hand, or any other body part, then move it out of your way. You now need to clean it up, especially if the drain plug magnet had a lot of crap on it, also if the gasket didn't get ruined between the 3rd member and the housing, reuse it, if it was ruined, then you need to scrape all of it off with a razor blade and buy a new one(do this anyway before taking anything apart) and install it after everything is clean, now I suppose that one should use a little gasket sealer on it, I don't myself, but that is me. Now reverse all the above, put the new to you good 3rd member in and connect everything back up, bleed the rear brakes, fill the diff with gear lube using the to fill plug(adjustable crescent wrench), drop it on the ground and you should be good to go. 1 Quote Link to comment
Stoffregen Motorsports Posted October 1, 2016 Report Share Posted October 1, 2016 Third member is often used to describe the whole unit. Housing is usually the bare cast piece that the carrier and gears are installed in. The carrier is the rotating assembly that the ring gear is bolted to. Many different names cause lots of confusion when discussing auto parts. 2 Quote Link to comment
datzenmike Posted October 1, 2016 Report Share Posted October 1, 2016 If careful you can pull the axles out just enough to separate the spline without disconnecting the brake line. I did this last spring on my H-165 in my 710. I know... not a truck H-190 but the idea is the same. 1 Quote Link to comment
Scgreen620 Posted October 1, 2016 Author Report Share Posted October 1, 2016 Yes guys sorry and no it's not an age thing .. I just have no idea what it's called I thought since here is 3 pieces to the drive shaft, the one closest to the differential was called the 3rd member 1 Quote Link to comment
G-Duax Posted October 2, 2016 Report Share Posted October 2, 2016 No.... 2-piece driveshaft. Front driveshaft, and rear driveshaft. And google '3rd member' images, and you get these: https://www.google.com/search?q=3rd+member&safe=off&rlz=1C1AOHY_enUS708US708&espv=2&biw=1164&bih=574&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjjvJDU7LrPAhXFOyYKHX3kADwQ_AUIBygC 1 Quote Link to comment
Scgreen620 Posted October 3, 2016 Author Report Share Posted October 3, 2016 Mine has 3 u joints does that mean it's two piece? 1 Quote Link to comment
Scgreen620 Posted October 3, 2016 Author Report Share Posted October 3, 2016 I will have to replace that soon too I'm sure 1 Quote Link to comment
datzenmike Posted October 3, 2016 Report Share Posted October 3, 2016 Mine has 3 u joints does that mean it's two piece? yes transmission U driveshaft U driveshaft U differential 2 Quote Link to comment
Scgreen620 Posted October 4, 2016 Author Report Share Posted October 4, 2016 For the 3rd member piece ... Can I buy them already rebuilt or would I have to do that myself? Quote Link to comment
datzenmike Posted October 4, 2016 Report Share Posted October 4, 2016 Well you can simply buy a used one from another truck and keep on trucking. Or have a shop replace the bearings or the actual gears... but it requires special tools and gauges to set the gear lash properly. Quote Link to comment
Scgreen620 Posted October 4, 2016 Author Report Share Posted October 4, 2016 I've went to a couple of shops they said they don't carry replacement parts Quote Link to comment
datzenmike Posted October 4, 2016 Report Share Posted October 4, 2016 Then they simply don't want the work or are not the right shops. Maybe a shop that specializes in differentials? Nissan may have the parts and most people can read the part numbers from the old bearings and cross reference them. As I said these need special tools and knowledge to set properly. Get a used one. 1 Quote Link to comment
G-Duax Posted October 4, 2016 Report Share Posted October 4, 2016 I've found a few bearings on eBay, but not a steady supply. And +1 on special tools. Dial indicator, dial calipers, bearing puller, and a hydraulic press, as shims on both the pinion, and diff are under the bearings. So any adjustments require the bearings to be pulled off, to change the shim(s). The biggest pain in the arse diffs I have ever worked on. Althoug all diffs have the pinion shim under the bearing, most have the diff shims on the outside of the bearing, like an R200. The R160/180 is shimmed with gaskets on the bearing retainers. And really easy diffs have threaded bearing adjusters, like the little Toyota units, and the Mazda. Just remove the bolt-on lock tab, and turn the retainer in or out. Quote Link to comment
Scgreen620 Posted October 5, 2016 Author Report Share Posted October 5, 2016 Yea people are getting lazier and lazier Quote Link to comment
Recommended Posts
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.