Shifting questions

[soviet_merlin]

13 minutes ago, dbm7 said:

'Did' work on them is more accurate ~ on the R31 Skyline forum, you can spot me as 'Solder'... I've written quite a bit about the 4R01 boxes there, and I ended up reverse-engineering the older TCU type operations, so we could fudge a custom TCU to pull off other tricks...and like all things, when you do it a lot, see the failure patterns, have to find parts etc etc, your head ends up filled with whys and wherefores...

Makes sense, thanks! Consider me very impressed. And I very much appreciate the effort in documentating all of it. You'd be surprised, or maybe not, how many people this reaches who search for things online.

Anyways, I shall continue to read all of it, understand maybe a quarter, and hope that some of it sticks if I ever end up in a situation where it's relevant

[dbm7]

39 minutes ago, soviet_merlin said:

Makes sense, thanks! Consider me very impressed. And I very much appreciate the effort in documentating all of it. You'd be surprised, or maybe not, how many people this reaches who search for things online.

Anyways, I shall continue to read all of it, understand maybe a quarter, and hope that some of it sticks if I ever end up in a situation where it's relevant

No worries, now that I'm closer to 70yo than not, this sort of stuff will one day be 'lost knowledge'... and even now, I wonder just how many folks out there have the Kent-Moore J34291 shim setting tool set to set end clearances rebuilding these...but right the now, there's less and less hard parts available, and you'll be headed to the wreckers to buy a donor box if it's worn out...(or pay a shop to do exactly the same thing). In a way, it's fortunate the 4-speed was so popular, because there's still heaps of consumables (banners kits, bearings & plates etc) around ~ these early 5-speeds weren't exactly that prevalent, so there's not quite as much about for them... but it's a race between perceived demand for these parts, versus how much they fetch at the shredder for recycling purposes...

[DRoc81]

1 hour ago, dbm7 said:

'Did' work on them is more accurate ~ on the R31 Skyline forum, you can spot me as 'Solder'... I've written quite a bit about the 4R01 boxes there, and I ended up reverse-engineering the older TCU type operations, so we could fudge a custom TCU to pull off other tricks...and like all things, when you do it a lot, see the failure patterns, have to find parts etc etc, your head ends up filled with whys and wherefores... there was a reason Nissan went with these in more than 60models over 16+ years... all in all, the JR401E based design is an interesting study, as Nissan changed things over the years in a never ending battle against them lunching on themselves <grin>...by the time the RE4R01A rev.C came out (often referred to as RE4R01B), they'd more or less perfected the design...

 

 

8 hours ago, dbm7 said:

I'll just reiterate that it's best to do all the wiring diagnostics, before even thinking about buying replacement solenoids ~ that is, be absolutely sure the solenoid is bad.....ie; bad connector(s), rodents chewed through a wire, etc etc. If you don't so this, you can fork out all the money for solenoids, only to find something else is wrong (this'll make you cry if you pull the valvebody only to find a broken wire is at fault...

...some more glue on the solenoid packs -- this is the RE5R01A shift solenoid assembly....

...these are all shift solenoids ~ ostensibly they're the same as the shift solenoids from the 4-speed auto....

...this is the RE4R01A solenoid set...

...with these, you have 3 shift solenoids attached to the plate, and the separate solenoid is the EPC solenoid (line pressure control) -- with both designs, the TC lockup clutch solenoid (also PWM so they could slide the clutch shut), is located on the lower valvebody half....

...(story time)...back in the 90's, it was a common fault that the EPC solenoid (or TC-lock solenoid) would fail, but Nissan only sold them as part of the assembly (think ~$350 at the time) ~ thing was, Isuzu also used these boxes in light commercials, and you could buy the PWM solenoid as a separate part, so it was possible to buy/use that solenoid (around $65), and make it fit (remove the circlip, fit to old plate and deal with wiring)...making it a more cost effective repair.

I've not seen the RE5R01A shift solenoid assembly, but with the 4-speed RE4R01A it was possible to hack/fit a single shift solenoid onto an other working set, using a donor solenoid from another set with failed EPC....(by rights the whole set should be replaced), but it ends up being a question of how much life is left in the box itself ; sometimes it's a viable repair to fix one solenoid, just to get another 100k of road miles out of it before it needs first overhaul...other times the box is that old/worn, you're as well doing first overhaul and replacing the solenoids and starting fresh...

What Nissan did here with the 5-speed, was relocate the EPC solenoid to the lower valvebody (next to the TC lockup solenoid), and stuck the direct-drive clutch solenoid (for the extra gear) where the EPC solenoid used to be on the 4-speed....I can only imagine they did this for serviceability ; the PWM solenoids are most likely to fail, and it's a doddle to drop the pan and change these out (as opposed to dropping the valvebody itself to get at a top mounted EPC)...

...also keep in mind, that some BMW 3/5 series & Mazda (and maybe some Ford/Mazda rebadges, not sure), also used the RE5R01A box under a different name/part number...not saying parts availability is any better, but sometimes it helps to know this when it comes to NOS floating about in the EU....

HTH

 

Dang.....  that is some good info.  Thank you. 

 

Yes, I plan to do some troubleshooting before I actually just throw parts at it.  I was doing some investigating on parts, just to get a head start, if wiring and stuff all looked good.

[DRoc81]

1 hour ago, soviet_merlin said:

Makes sense, thanks! Consider me very impressed. And I very much appreciate the effort in documentating all of it. You'd be surprised, or maybe not, how many people this reaches who search for things online.

Anyways, I shall continue to read all of it, understand maybe a quarter, and hope that some of it sticks if I ever end up in a situation where it's relevant

Yes, me too!!!!  I need to find a something that has all the abbreviations for what these cars have LOL