Tranny Howlin (*Gulp*)

**AlphaBetaBase** · 05-03-2008

I took the car in for service to check the tie rod. The guy showed me on the lift how the tranny was howling under acceleration.

That knock noise I heard after I go from reverse to drive and start to pull off? They think its the diff.

I did a few searches to see everyone's tranny swap responses but my requirements are unique. I got 160k on it w/ the Gen V engine and GT tranny. I don't plan on racing but I don't want to give up the GT gearing. I plan on keeping the car for another 2+ years at least as I can't sell it for a good value due solely because of mileage. Wanna know my choices:

1) Original shop: They quoted $1600 for parts + install to rebuild the GT tranny. I don't think this is efficient as its still connected to the GTP. Lower expected life.

2) zzp tranny: I reviewed the website. I understand the choices and I guess it will be $1800+$600 in parts/labor. Not the cheapest.
https://www.zzperformance.com/grand_...sg=1&catid=105

3) Rebuild 4t65e to 4t65e-HD: Not sure of the cost as I don't know what's happening with it now. I assume flexplate and diff are the issues. I assume it will be similar as tranny costs are usually labor.

Thoughts? I'm curious on parts+expected labor. Any other options are well welcomed

BTW: If there are any guesses on why it is howling, feel free to contribute.

**Trannyman95** · 05-03-2008

Does the noise only only happen at a certain mph or rpm? Only in certain gears? Does it make the noise in neutral or park? A knock/clunk from reverse to drive can be a number of things, normally exhaust hitting something but it could also be inside the trans but not common. Were the axles/cv joints inspected? If the planet gears on the diff are at fault it will make a howling noise directly related to vehicle speed. Will the noise dissappear if you put the shifter in neutral while going down the road? You do have a pretty high miles on the trans so it may just be on its way out. There is nothing really different between the GT and GTP trans other than HD diff, larger torque converter, and different gearing which is interchangable. My high performance street transmissions start at $1450 which will be enough trans to get you into the low 13s/high 12s no problem. Parts cost shouldnt really matter unless you are working with a shop this is charging strictly off of what needs replaced plus rebuild labor, but most shops dont generally price that way. What kind of power does the car make or have you made any track passes to get 1/4 mile times? I sell HD diff upgrades for $250 which will include an HD diff, diff cover,and an HD diff specific output shaft. You still need to use a GTP passanger side axle as the inner hub is larger.

**AlphaBetaBase** · 05-03-2008

1) It starts to make the noise as soon as you get past 20 mph or so. This when it was on the lift. The howl was pretty apparent it was coming from under the trans pan. When I drive it, I hear it more so on the highway going straight and if I make a right turn. It goes away when I move it to the left. I didn't think transmissions would care about turns.

2) The howl occurred on the lift in 1st gear and I can hear it on the highway (if it is the same howl) while in OD.

3) I got the right wheel bearing replaced this morning. They didn't mention the CV joints.

4) I'll try putting it in neutral to see if i hear it. Good idea!

5) With the mods, the dyno got it at 197 HP and 273 ft-lbs. If 20% loss, that's 236 hp and 327.6 lb-ft at the flywheel. I wasn't too happy with the hp not increasing but the torque is pleasing and probably explains why the tranny is going.

5) I'm pretty sure this shop isn't going by what parts they need to replace. They just wrote it down on a pen saying $1600.

I will try driving the car in neutral to see if I hear anything. One very important point is my front tires are really low as I thought that was the culprit.

Question:
1) How does that trans shift. Is it very firm? I was leaning more towards softer Daily Driver shifting.

2) Would the diff make that *pop* noise as you start to pull off?

Thanks,

**Trannyman95** · 05-03-2008

The best way to rule out the wheel bearings is to have the front in the air and listen to the with a stethoscope to verify which side could be the cuprit. Did replacing the right side help the noise at all or not? When the car is in the air there is really no load on the bearings so they may not make the same noise or level of noise as on the road, but also remember that the axles are at a much greater angle and can make more noise in this state as well. The transmission shouldnt care if you are going straight or turning but the differential may show different noises doing this, but there should be no noise going straight from the differential as everything is spinning at the same speed so there is no side load on the gears from spinning different speeds. Tires can certainly cause noise issues but you said it made the same type noise in the air and tires arent going to make road noise up in the air so that rules that out. Swaying the car left to right at around 30-40mph can you tell if the sound comes from one side more than the other? My transmissions are built for the mods done to your car and how it performs and they are not all the same. I do this for your exact reasons, you dont want really firm shifts nor does your setup require it given those power numbers but it will be a much quicker feeling shift than stock.

**AlphaBetaBase** · 05-04-2008

Howling on the road: Well, the wheel bearing got rid of the howl I heard on the road. Straight, left, right on the highway. Nothing. So the howling on the road is done.

Pop noise at pull off: I haven't heard the pop/click noise pulling off yet. I'm still checking for it.

Tires: Looks like the wheel bearings cause the noise so they aren't the culprit. They just need replacing.

Howl in the air: There was definitely a howl coming from the trans pan when I was under it. However, I don't hear any noise at all now that the bearing is replace. Therefore, its safe to say the tranny is starting to go. it I'm tempted to take the ignorant route and just wait it out until I can afford a new tranny. Murphy's law states to do it now instead of being stranded out in the middle of nowhere. But tires take priority as they are close to bald

BTW: The car is running very rich. This is probably why the hp isn't high with all my mods i.e., CAI, Hi-flow cat, u-bend delete, 180 stat, with maintenance kept up.

Question: With all the info above, what could cause transmission howl? Is it a "could be anything/need to see inside" situations?

**Trannyman95** · 05-04-2008

It is possible that the noise you heard in the air was the wheel bearing and will trasnmit throught he shafts. It is going to make noise itself though it shouldnt make much noise. If everything is working fine then I would just drive it until something more sever pops up.

**AlphaBetaBase** · 05-04-2008

Wow. Never would have thought of that. It wasn't making much noise. I'll ride it until something else happens that is more noticeable. I figure it took a beating the two severe winter days where I drove it the hardest it ever has been driven.

Thanks!