[stevenhinkle75]

Hi everybody! I picked up a 2006 Sentra for 500 buckeroos, lol. It's got the 1.8 ( QG18DE ) with the auto trans ( RE4F03B ) and I'm considering making this car my daily driver but I've heard bad things about Jatco transmissions. It's got 220,000 miles presumably on this transmission and it seems to shift fine. The tranny oil isn't dirty and looks good. The shift between first and second is a bit firm but I figure that's probably normal. So my question is, how reliable are the 1.8L auto transmissions? What experiences have you guys had?

I tried the search function but couldn't find much info that way.

 

[stevenhinkle75]

I just had to replace my transmission but it was the RE4F04B, lasted 289K before giving out. Judging by how it was shifting in the latter part of its life (soft shifts/refusing to kick down) It should have had major service performed if not been overhauled when it hit 200K. Pull the pan and look for metal flake and buildup on the magnets.

Very good to know! I imagine the 4B and 3B transmissions are mostly similar. I'll drop the service pan one of these days and see what's what. Thanks for the reply!

Anybody else want to chime in?

 

[stevenhinkle75]

I just had to replace my transmission but it was the RE4F04B, lasted 289K before giving out. Judging by how it was shifting in the latter part of its life (soft shifts/refusing to kick down) It should have had major service performed if not been overhauled when it hit 200K. Pull the pan and look for metal flake and buildup on the magnets.

I changed the tranny oil the other day and I did see a small amount of metal flakes in the bottom of the drain pan along with a few pieces of metal 1/10th the size of a dime. I didn't get a chance to drop the pan and look at the magnets though. I'm sure they're probably covered based on what I saw. I have one more question for you if you don't mind. My Sentra seems to shift very smoothly from 2nd to 3rd and from 3rd to 4th. I would also say that the shift from 1st to 2nd is smooth as well but there is a quite small amount of jerk / lunge when shifting into 2nd but only sometimes. I think it might be normal but I don't have anything to compare it to. Do B15 sentras normally just kinda jerk a small bit when going into 2nd? I've owned like 13 different manual transmission cars but this is my first automatic and don't really know what to expect. Just glad it's not a CVT... ugh.

 

[stevenhinkle75]

Now I'm no transmission expert but my general feeling is when the car is lunging into gear, thats valve body wear. Theres a specific known issue with the RE4F04B's as the valve body sealing elements age they will cause the engine to over rev or "flare" before dropping into the next gear. Mine did it before the rebuild, I dont think its a stretch of the imagination to think your valve body needs some attention at 220K. If you wanna get your hands dirty TransGO makes valve body rebuild kits for 3B & 4B's, good luck finding a shop that will do this, out of the dozen shops I called around me only one would install and told me in no uncertain terms it came with ZERO warranty.

I believe you are right. I think the valve body on my Sentra is sometimes engaging correctly and other times delayed. The slight lunge I'm experiencing between 1st and 2nd is random. So since my last post, I've finally put a decent amount of miles on the car after buying it and now I'm noticing what seems like a slightly more pressing issue with the tranny. There is a strange swooshing noise coming from the transmission when the car is cold. The swooshing sound lasts for about a second, stops for half a second and then repeats until the engine is warm. I believe it's a worn bearing but I'm not 100% sure. Starting to mentally sort this car into the more "beater till it blows" catalogue of my mind. So I think I might try some Lucas Transmission Fix additive because I've heard of quite a few people that have had some luck using it. All it essentially does is raise the viscosity of the transmission oil but I believe it could be enough to protect the noisy bearing. If I get another 24,000 - 36,000 miles out of the car, I'll be happy. So 242,000 - 256,000 miles total. I'll post my results to let others who may be reading this know if it worked. Thanks again for the reply!

 

[stevenhinkle75]

So this is embarrassing but it was something completely separate from the problem I thought it was. The car was low on power steering fluid and the swooshing sound I was hearing was from the pump creating bubbles as it was deprived of fluid. It was caused by a leaky power steering reservoir. I believe it's probably a common problem on these cars. Just wanted to clear that up for anyone who may be reading this with a similar issue.