Any car/truck gearheads here? Need mechanical advice?

[LSchafroth]

If anyone can help me. I have a 1997 Bonneville I put a used transmission in over a year ago.

Lately it has started to make a loud popping sound when under acceleration. It sounds and feels like splines slipping. It does it in all gears, forward and reverse.

Every once in a while, it will catch and I can gun it and go through all the gears and accelerate smoothly, even under full throttle.

Can this be a bearing? CV joint? Torque converter?

How can I troubleshoot this?

The CV joints look good, spin without wobble. No tears or cracks in the boot. No play in the bearings at all.

Lannie

[lordsmurf]

I'm not a gearhead, but one is in the room with me right now (coincidence!), so I read your post to him, and this was his reply...

The easiest way to troubleshoot this is also the hardest way to diagnose.

Take the transmission out, disassemble it, examine it piece by piece, clean it, then put it back together, making sure everything is greased as needed (if needed -- depends on part), and putting proper transmission fluid back in.

Be very sure to read the 97 Bonneville book, and use the exact proper required fluid (and amount).

A Haynes manual may help.

[LSchafroth]

If I take it out, I will put in q rebuilt. I'm just trying to figure out if I can replace anything else or see if it is anything else.

It makes no sense to me that it will work through all the gears perfectly one time and not the next.\

Lannie

[Xylob the Destroyer]

That's definitely NOT a CV joint. If your constant velocity joints were going you'd feel it in the steering wheel at all speeds and more so when turning.

[zzyzzx]

How many miles are on the car? How many on the axles? How many on the transmission. Does it make the noise when turning?

In contract to what was written above I do suspect the CV joints. I've had them wear out but still have perfectly good boots on them. Still cound be the transmission though. Or ball joints, or tie rod ends, or some other suspension part.

[Xylob the Destroyer]

When my CV joints were going the boots were still fine, but the thump thump thump in my steering wheel was ever present...

[LSchafroth]

It has 197,000. The hub assemblies are fine. I took them off and checked them. The CV's are fine and suprisingly in great shape.

Put the car on jack stands and had my son power brake while giving it throttle and the pop comes from the transition from just under the bell housing where it goes to the passenger side.

It must be the gears in that joint internal. It's toast.

I have found a used one with 68K on it for $325.

Time to yank it out again. fun fun...

Thanks guys!

Lannie

[LSchafroth]

Long overdue reply. The transmission was toast. I also discovered that year had a terrible transmission as well. After putting in the second one, we got a good one.

Still got 400K out of it.