​​​​Hello all,

I've been trying to find this problem but all I find is newly built trans. Randomly in reverse it feels like my brakes are on and the engine will stumble. I've tried the put it in neutral and see if it moves forward, it doesn't. I just tried over and over to recreate it and I can't. It shifts through all gears in D and I can make it shift also through all. I tried coasting in neutral to see if it felt like brakes were on and still nothing. Fluid is full and looks good. It does feel like it slips and takes some time to grab the next gear but I already planned on a shift kit at some point. Any ideas or suggestions are appreciated
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thanks a lot!

Oh sorry, it's a 2000 trans am, 110k miles. Fully stock minus a lid.

 

Just to be clear - as far as you know this is the stock never-rebuilt transmission?
The trans increases line pressure in Reverse which is making your engine "stumble". From this and you description, it doesn't sound like a shift linkage problem.
Unfortunately my limited experience does not include "reverse" problems. Hopefully one of the experts here will chime in and say "Yup its this...". More unfortunately, I suspect it will require a rebuild.

 

Yes as far as I know it's not rebuilt. I've only had it a little over a year so there is about 22 years of unknown but considering the miles I assume it hasnt been touch. It is a 4l60e though so ya never know. From what I've read, and I don't know a damn thing about a transmission, is that when it should be going in reverse there could be a crack in whatever makes it go forward so it's leaking through and trying to do both at the same time basically. I'm hoping its something else though because it's so random when it happens. I've read next time it does it to throw it in neutral and see what it does. It always is slow to switch between drive and reverse from neutral so I'm hoping maybe I click it in and throttle it to soon when I'm not thinking. But like I said I don't know these things so maybe that's stupid to think.

 

The thing I am not clear on is this a long time running trans or a fresh rebuild? Next what happens when you place it in low 1 ? The reason I am asking is it sounds to me like if its new build then the ring holding the low roller in case may be missing or if older the lugs could have broken out of case, when the low/rev clutch is applied if that is the case then it will push forward on the planetary assemblies causing a bind up in Manual low one and to a greater extent in reverse due to higher line pressure.

 

as far as I know it's the original untouched trans but I've only had it for 15 months. It feels totally fine in l1, any of the gears when I'm shifting it. Minus some slip and a little slow to switch into drive and reverse it's never felt bad. Based off the name I'm sure you're the guy for this topic.

 

The only other thing I can think of possibly 2nd or 4th accun leaking and partically applying the band .

 

I really appreciate your input first off. Secondly aren't those the plastic pieces in the valve body that sonnax shift kit switches out for a better design?

 

Yes they can leak or crack .

 

you think that's more likely than the crack forward drum or whatever the worst case scenario is? Sorry been reading and I see scary things and can't remember all the million names of transmission internals.

 

No fluid is sent to the Input drum in reverse so forward is out of the picture, The reverse input drum and low/rev are applied , The reverse input drum apply could be cracked but hat will generally make a slip not bind. The snap ring could have come off the return cage in the rev input drum and applying pressure to assembly but I do not think that would be enough to bind up. I would check the accumulators first , Then well if not there pull and go inside and may as well rebuild it or replace at that point.

 

I might have found it and feel dumb as hell if so. Wheel rub? I bought this car lowered and it needed front tires real bad. I put new struts in the front, brought it back to stock, and it has c6 18s in the front so I just put whatever the OEM tire is for that. Well today I bought new rear tires, already had the c6 19s and put stock size on that but the rear is lowered still. Well I like how it looks so I thought maybe I should drop the front back down. When I was looking at the clearance I noticed it's totally rubbing on the front. Think that could be it?

 

no, not when you mentioned slipping, and engine stalling. I would have a good transmission shop look at it. ...

 

Could be. I would check it out for sure.

 

Its possible . not the stumbling but that may be an unrealted event, Several other things happen in reverse that could affect idle.

 

when I was testing it a while back I couldn't replicate it and im wondering if it's because I was backing up completely straight. It rubs at about half turn.

 

I know I have a vacuum leak too, I think it's my intake manifold. Plus side is I have a ls6 intake in the closet.

 

It's not rub. Backed up maybe 5 feet and then reverse was just gone. Revving it up to test and it had less go than when you're in drive and it's just pushing itself. I'm hoping it isn't completely gone so I can make it through the holidays and my daughter's birthday. Gonna try a shift kit as mentioned the cracked accumulators and go from there.

 

When it rains it pours. Was driving and lost 4th on the freeway, got off as quick as I could but was doing 65ish in third, smelt burning on the off ramp. Now feels like I also lost 3rd. Life just keeps getting better. Probably toast at this point but it's my only option to keep driving it. Don't have funds for anything except another 60e from a junkyard but that's obviously a gamble and a bandaid at best.

 

Sorry to hear that your trans has decided to give up the ghost. Hope you can find a way to get up and running again soon. Where are you located?

 

Thank you I appreciate it. It's been a very trying few months even outside of car problems/maintenance. I'm in Denver. I'm ordering a shift kit and see if that fixes it, doubtful. If not then junkyard it is, swap over the valve body, put in a new Corvette servo, and I'm thinking the i6 TrailBlazer torque converter. Might not be the best route but I despise the 60e so I can't justify a rebuild/rebuilt and need to do this as cost effective as possible.