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Discussion Starter · #1 ·
Short version: Shifter slides into reverse gate with ease and nothing happens

I was having a problem where my reverse lockout wasn't working, on 4-5 occasions when I was shifting fast from 4-5 I'd hit reverse and grind since I bought the car in August. Well the last time it happened was 2 weeks ago and ever since reverse would pop out 90% of the time and be pretty hard to engage and grind when it wouldn't. (I'd never try to hold it in and keep it grinding and force it).

Well we had a snow storm last night as those of you in the northeast know, I dug the T/A out and was rocking it very gently to loosen it and for once reverse wasn't even grinding or being difficult :D. Well after 2x engaging it, it just quit :mad:. Now it slides into the gate with zero resistance, I can release the clutch and nothing.

I did some research and saw some posts talking about removing a plate in the back of the trans and servicing it in the car/ replacing the gear and shift fork. I'd assume the blocker ring is gone? I've read conflicting posts on whether there is a synchro on reverse or not.

I haven't had a chance to check the fluid level yet but would low fluid impact reverse first? Seems strange that it just slides in so easily.

I'd really appreciate any advice, the timing is very bad for me to be pulling the trans and sending it off for a rebuild.. Hell I don't even know if I could do it safely on the street where I do all my work, thanks guys.
 

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my theory is that the reverse shifter fork was stressed out (bad) by those missed shifts, and you finally busted the thing. but that's just a guess..

i cant believe you actually knew your reverse lockout was faulty, and still managed to shove it into reverse at speed like that.. that was dumb. i know this sucks, but man, you really did this to yourself.

yeah t56 has a wimpy reverse synchro in it. the transmission would go into reverse with even no fluid in it. you'd probably get some action out of it with a worn down synchro.

i promise, it'll have to come apart. it would be really foolish to try to do this on the car. when something in the transmission breaks, every single part must be removed and cleaned. there are shredded chunks of the broken component everywhere, and gear oil being slung around is a great vehicle for broken crap to end up in between a couple of gears.
 

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Discussion Starter · #3 ·
Yeah I did some more search and I'm planning on doing a rebuild, doesn't seem too bad. I didn't know the lockout was faulty until the 3rd time it happened (which was about a month or so ago). I started researching it more and was planning on diagnosing it when I had the chance (its been freezing cold lately) so fast forward to now.

I'm hoping I can find a spare trans that needs a rebuild so I can rebuild that for the time being, then just remove my trans and swap my flywheel/ clutch and go. Then I can rebuild my original trans and sell it. Worst case scenario the car will be down for a while if I can't find another tranny.
 

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or just get a low mileage wrecker trans and throw it in there, it'll probably be fine. they aren't that bad to rebuild, but i wouldn't make a hobby out of it.
 

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Discussion Starter · #5 · (Edited)
or just get a low mileage wrecker trans and throw it in there, it'll probably be fine. they aren't that bad to rebuild, but i wouldn't make a hobby out of it.
This is NYC, so all the yards in a 100 mile radius charge extreme prices and half the time its junk. I've seen T56's with problems go for about 2-300 before, $500 for rebuild parts and thats not a bad deal to have a refreshed trans. A used T56 thats being sold as working is 1500 easy, and who knows how it was treated.

My main concern is that I do all my work on the street, so I'm wondering if I'll be able to drop the trans safely with the car propped up on the side or on ramps.

*Also I might as well ask about this.. At very low speeds (under 10mph) when in first I'd be getting a rattle, like a light grinding. Is it possible that first lost it's press fit? When I had it up on the lift last time, I rotated the drive shaft and it would rotate about a good 1/2" and something in the trans would clank. Any input?

Thank you!
 

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If I were in your shoes, I would fix it with it on the car. It's going to be cheaper that way and you know what you have opposed to someone else's mystery trans.

It's certainly not ideal to do this kind of work with the transmission in the car and if you had any way to work on it off the car I'd definitely do that. But I know where you're coming from. I used to do all my working on cars curbside and in parking lots when I was growing up in Philly. The biggest issue really is cleanliness. Keeping dirt out of the transmission will be difficult. If you can, I would lay down some clean cardboard and have new parts wrapped nice and neat prior to starting.

With the missed 4-5 shifts, you likely broke the reverse fork or sheared off or severely damaged the engagement teeth in the reverse gear or synchro. Depending on their return policy, I'd order all new parts and return what you don't need once the repair has been made. That list would include a new reverse gear, blocker ring, reverse thrust washer (the plastic one should be replaced), reverse shift fork, reverse fork snap ring, fork pads, and new keys and springs for the synchro. The reverse synchro can be flipped around so you have fresh teeth as only one side is used.

Any broken pieces will be captured by the case magnets. Any loose pieces would have likely done their damage at the time they broke, they don't typically stay lodged as centripetal force and opposing gear teeth would keep them from staying between gears.

Reverse gear is quite easy to access without any special tools other than C-clip pliers. Everything should come out without any pullers, but sometimes they are needed for the speedo gear and reverse synchro. It will be a bit tricky to get the rear housing back on as the reverse shift rail wants to fall down and access to it under the car is limited.

Your first gear is not press fit on to any shaft, it free floats on it's own bearing until it's selected. The only thing press fit is the 1/2 synchro hub, but I doubt there's an issue. A lot of T56s have a light gear rattle when starting off. Google it, you'll see it's quite common. I wouldn't worry unless it's excessive.
 

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Discussion Starter · #7 ·
Thank you for all the info and advice firehawk!! I have a line on a fully built trans with some goodies for roughly $1500+ shipping (may be able to go lower on price) so I will see how much it will be to ship. Then I could sell my core for $700 or so.

At this point I think it'd be easier to remove the transmission altogether, that will be interesting using floor jacks/ stands only. Who knows if I'll be able to get it high enough..

As far as the rattling/ grinding noise, you can easily here it outside of the car standing 5-10 feet away. Its a little embarrassing but so far for the last 2k miles it hasn't acted up any.

By the way, I found reverse again tonight! I was sitting at a stop light playing around, I moved the shifter all the way down to the right without clutch. I pushed it in just as I was about to enter the gate and it popped in ever so lightly! I tried it a few times and it grind a tiny bit and wants to pop out but its there! Good for emergency situations as I'm still DDing the car for the time being, I wonder how long it will hold before it blows completely.

Thanks so much again!
 

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Well that's certainly an option if you want to go that route, but considering it will cost $800 after you sell yours and the hassle of storing/shipping your core, I was thinking it would be easier and cheaper to do the repair yourself. The parts I listed will run you $250 if you need all of them, and if your reverse gear is good you can subtract $185 from that number. Heck if it's just the fork, that's only $20. And it's only a couple hours of work.

Just sayin'...
 

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Oh and I forgot mention that the 5/6 gear cluster that is splined to the output shaft can start to eat away at the splines. I had this happen to mine, and could possibly be the source of your noise. It really is a poor design that limits 5/6 gears to cruising gears rather than for spirited driving. I've also heard this contributes to a common vibration issue with F-bodies around 90mph, but I can't say that's true or not.
 

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Discussion Starter · #10 · (Edited)
You're right, I think I'm going to go for a quick and dirty fix since the rest of the gears shift perfectly fine.

I'll do as you say and buy all the parts I need beforehand, drop the trans on the street/ bring it into my porch and do the repair over a weekend/ week or so depending on if I run into any complications. Hopefully I can wait it out until the temps rise into the 50s at least.

Is there any site you would recommend to buy those parts from? I was looking through your rebuild thread today, nice write up!

So in essence, if I have the snap ring/ c- clip plies and a puller with fabbed extensions I'll be alright.

As far as vibration goes, I have a strong one at 65-70mph and thats cause the idiot PO installed a poly trans mount along with stock rubber motor mounts. It rattles the interior like crazy!!

Thanks again so much!!
 

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Is there any site you would recommend to buy those parts from? I was looking through your rebuild thread today, nice write up!
Thanks!

I like Tick Performance, but I also used D&D performance and The Gear Box for different things. I did have some small issues with D&D, but after speaking with Joe everything was resolved. Their website doesn't update with what they have in stock, so you could order parts just to find out after you already paid for them that they're on back order. And I was also charged more than the advertised price for some things and was told "the price went up for those". I wasn't very happy with that.

So in essence, if I have the snap ring/ c- clip plies and a puller with fabbed extensions I'll be alright.
You won't even need the puller extensions if you're just doing reverse. A decent pair of C-clip pliers (I ended up with a craftsman pair), some snap-ring pliers, and a small punch for the shifter offset lever roll pin are about the only special tools you need.

If you haven't done so already you should download the T56 service manual for reference. I printed mine out and bought a binder and some page protectors so I could reference it as I worked.

Good luck!



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Discussion Starter · #12 ·
Thanks again, much appreciated. I definitely will download the manual once its closer to go time, hopefully I can hold out until its in the 50*s. I'm not going to possibly need a puller for the speedo gear and reverse synchro?

I wish I could go ahead and build the whole trans but time is not on my side and I plan on selling the car in a few months anyway.
 

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I guess it wouldn't hurt to have that stuff handy, but the reverse synchro should come off without a puller. The speedo gear calls for a puller, but mine (and others from what I've read) came right off without one and you wouldn't need to modify a puller for just that, just use a large one. You could probably get away with lightly banging it off with a plastic mallet too.

You should also make sure to mark the orientation of the synchro hub to its sleeve; it should be reassembled exactly as you found it. The key retainer on the unused side can be swapped to the used side so you can use the fresh synchro teeth when it's reinstalled.


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Discussion Starter · #14 · (Edited)
I'm not sure what to do..

Theres a guy on LTXtech with a freshly rebuilt T56, heres what it has:

New bearings, shims, snap rings, upgraded 3-4 steel shift fork, all bronze pads, all new syncros, new reverse gear/ associated parts, along with a new napa clutch. The case is also polished but its unnecessary for me.

It would be nice to have a brand new trans essentially with bearings and all. He showed me a pic of his receipt from D&D and just the parts were over $1200. He wants $2k shipped but I think I could knock him down 100 or so.

I don't know what I'd be able to get for mine with the blown reverse, or if it would make more sense to tear it down after removal/ fix reverse and try selling it since its perfect apart from the low speed rattle.

What do you think? Is $900 as a core for mine realistic with the reverse problem?
 

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That's not that bad of a price shipped. If that's the route you want to go, jump on it. I don't think I'd pay $900 for a T56 core with a bad reverse, but someone might. They do seem to go for a lot of money even with a lot of miles on them. It might take a while to sell at that price though, so it depends on how long you're willing to sit on it.
 

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I have a 94 with the t56 mine pops out of reverse when i give it to much gas..i heard it could be the dent system inside the transmission..the dent is what keeps it from popping it out of gear
 

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I have a 94 with the t56 mine pops out of reverse when i give it to much gas..i heard it could be the dent system inside the transmission..the dent is what keeps it from popping it out of gear
I assume you are referring to the detent assembly, but it does little to hold the synchro sleeve on the gear's clutch teeth. It also almost never wears out badly enough to warrant replacing, from what I've seen. It's just a metal ball held against a metal plate with detents in it to assist the shifter in "finding" the right spot to select the gear. The synchro keys are what keep the sleeve mated to the gear and the back cut on both the gear's dog teeth and synchro sleeve keep them together when torque is applied.

Popping out of gear is usually worn or broken fork pads, bent fork, or badly worn clutch teeth on either the synchro sleeve or gear.
 
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