Is 2 as good as 3 (synchro springs)?

[ybt502r]

I finally got around to getting into my transmission (SIII, B series). It was jumping out of 2nd and the whole drive train felt like it would move (I could feel it in the shift lever) on occasion. After extensive reading here and finding a broken 3/4 synchro spring in the oil when draining the gearbox, I guessed that the main shaft nut was possibly loose. (The transmission was a factory rebuilt unit with less than 10k miles on it, so I didn't think it was completely shot.)

Getting to it took a good long while - yes these trucks are all detachable in some form or fashion, but that does not mean it's not a whole lot of work besides. I found the mainshaft nut was indeed loose and pretty beat up (hammering it in with a screwdriver one supposes). Having a special castleated nut tool from our hosts on hand was the ticket - I got the old one off and replaced the lock washer and nut, tightening it all back up.

Next was the synchro spring...which defeated me, never mind that I had a step-by-step guide of how to insert new ones from others here who are obviously more of a magician than I. I tried and tried but could not get the synchro spring in the 3/4 synchro unit. I dropped it into the bottom of the transmission case at one point which took some doing to get back out. In the end, I simply gave up. I was not going to get that spring in. So I spent another day putting the Rover back together.

Loo and behold, the transmission is great, smooth and tight (well, you know what I mean there). It does not thump about and there is no tendency to jump out of gear.

So - how long can I expect to drive with just 2 out of the 3 synchro springs in place? It drives and shifts as normal, but I expect I'm putting an increased load on the remaining two. Anyone have any experience with this?

[BellaCoola]

I had the same issue...just before a long trip/expedition I discovered the mangled remains of mine when changing the gearbox oil...ackkk:eek:. Thought my trip was Kaput!

However, asking around on various sites and speaking with "experts", they informed me that it is not all that uncommon an occurrence and "chances are" everything would be OK.

I traveled over 6500KMs on the trip (and put the truck through hell), and never had any issues whatsoever. I ran it in 2wd, 4wdhi and 4wdlo throughout the entire journey.

Some day I will dive in and replace it, however if the truck is running fine I would not worry about it.

Cheers


www.freewebs.com/83s3109

I do tend to get a little unbalanced wobble, when coasting down hills, but at this point I have not had any issues with it.

Now saying all of this, there is the possibility that it could create more problems for me at any time and could fail so just be aware.

Heck...there are still 2 in there holding it together.:rolleyes:

[Daurie]

I"ve gone round and round with 3/4 gear syncro assemblys. I found that there is a slight lip on the forward edge of the spot the spring sits in and a angled pick helped me lift it up and over as I slid it forward. Long, angled tip needle nose pliers are a must. I also found that the springs sold individually as replacments are not quite the same as the ones I was replacing. They are somewhat longer and when you shift from third to fourth the bent part of the spring that is intended to retain it can make contact with the fourth gear on the mainshaft. Mine eventually got worn enough to snap off and the spring moved out of position. I eventually bought a new Genuine LR syncro and replaced the whole dang thing.. no issues since. The replacments wore out/broke within 500 miles.

[SafeAirOne]

3 springs are best. 2 is probably OK, though theyre less likely to center up the synchro well. 0 Isn't great, but you can get by. I've had zero for...going on 4 years now.