With anything above light throttle but less than WOT there is a strange shake or vibration that I can feel in the car. The problem is worst when making left turns.. The best way to describe it is bucking slightly. So, it's load based, but the frequency seems like it's rpm, not speed dependent.

A/F is good (on a wideband), I'm not misfiring, no codes, all mounts are good, and flex plate bolts are tight.

Anything else I should check?

_________________

95 SLE... a keeper. 241k miles. Low and Slow.
97 BMW 528i
98 Infiniti vq35'd i30: 13.3@104mph, 30MPG Hwy (RIP)
02 Jag X-type
03 BMW M5
05 Chevy Cobalt LS
07 Infiniti G35s 6MT (Sold)
07 Ducati Monster S2R 800 with DS1000 swap
83 Yamaha IT175K
72 Yamaha DS7: '74 RD250 swap, JL chambers

Info on dropping a 92-99: Here.

One of the axles. Far more likely. A diff would typically be doing it in either turn (I'm on my third, been there, done that).

_________________

Click here for mod list for both cars
93 SSEi, 95 SLE (supercharged) 97 Buick LeSabre Limited
PontiacDad at WCBF '04: Cruise control? That's like surrendering!
Comprehensive guide to troubleshooting, rebuilding, and modifying Eaton Superchargers

The boots are all good and the passenger axle has maybe 10k on it.

_________________

95 SLE... a keeper. 241k miles. Low and Slow.
97 BMW 528i
98 Infiniti vq35'd i30: 13.3@104mph, 30MPG Hwy (RIP)
02 Jag X-type
03 BMW M5
05 Chevy Cobalt LS
07 Infiniti G35s 6MT (Sold)
07 Ducati Monster S2R 800 with DS1000 swap
83 Yamaha IT175K
72 Yamaha DS7: '74 RD250 swap, JL chambers

Info on dropping a 92-99: Here.

Sounds fairly similar to my last tranny failure. Midrange throttle caused bucking. Slowly got worse and worse. Manual shifting to keep it in higher rpms and lower gears in town with light or heavy throttle made it liveable when it was the worst. Then it wouldn't move in 3rd or 4th one day.

To be honest, the rebuilder didn't know exactly what the problem was, but it didn't matter to me. It got new clutch plates, pump, etc, full rebuild essentially. I told him to replace anything that wears out no matter how good or bad it looked and put in a shift kit. I do know it wasn't an axle in my case because he left those alone. I don't remember it doing anything differently when I turned though.

_________________

WHITE WHINE - 1992 SSE Supercharged 236.26 ci (.040 Over) 15.090 at 90.2 MPH on old engine w/ slipping trans & melted O2 sensor - Gen 3 M62 and matching TB, Gen 2 Pully, Zillamotorsports Ported LIM, YT 1.72 Roller Rockers, SII FPR & Injectors, Hypertech Thermomaster chip w/ 160 Thermo, TransGo Shift Kit, Infinity/Pioneer Speakers & a 10" Alpine Type R Sub, all the watts, 140 amp Alternator, Ricepipe CAI w/ heatshield, Pilot Angel Eye Foglights, Clear Corners, '02 17" Chrome Bent 5's, Magnaflow F-Body Muffler and Hi-flo Cat, Ceramic Coated Ported Exhaust Manifolds, Fan Override, Monroe Reflex struts, red calipers
2009 G8 GT - Sport Red Metallic, loaded, SOLO Axlebacks, Rotofab Intake, Tuned, autodim mirror, removed intake manifold cover, HSV GTS triple gauge pod, two tone red-hot shifter and HSV SuperSport steering wheel, GXP rear sway bar and diffuser, 3.45 diff and various Camaro suspension bits, LED Taillights

My car does this exact same thing but it's mostly only under heavyish throttle buy less than WOT. I noticed it especially when turning left. Idk though it might do it in right turn too but I don't turn right a Lot.

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Clay
1997.2 40th SLE-138k
1968 Bonneville 400ci w/TH-400-40k
1999 GMC Suburban SLT-191k
2005 Escalade 253k-GINA

My original Half-shafts lasted 150+k, the new ones lasted about 10k...and no, boots don't have to be broken to have the half-shaft have play in it.

So, were your symptoms similar to mine..?

_________________

95 SLE... a keeper. 241k miles. Low and Slow.
97 BMW 528i
98 Infiniti vq35'd i30: 13.3@104mph, 30MPG Hwy (RIP)
02 Jag X-type
03 BMW M5
05 Chevy Cobalt LS
07 Infiniti G35s 6MT (Sold)
07 Ducati Monster S2R 800 with DS1000 swap
83 Yamaha IT175K
72 Yamaha DS7: '74 RD250 swap, JL chambers

Info on dropping a 92-99: Here.

My symptoms were different first failure even compared to second, so no saying because yours are slightly different than mine that you don't have a half-shaft failure of some sort. First failure, going straight anything over 55 deceleration would result in "thud thud thud thud" that would slow with speed. Then it changed to wanting to do that only when I turned slightly, but a hard turn would get rid of it. Now with the new half-shafts, it only does it when it's cold and just started to be driven for the day...(do NOT ask...it's oddball, I know)

Read diagnostics for a worn half-shaft...the symptoms vary so much it's nuts. I would go for the half-shaft first quite honestly...it's far more likely as Wren said.

Both of my new ones were bad from the word "go". Haven't replaced them yet because I'd have to realign the front end again, but I'll get to them in Feb. sometime. BTW...my mode of failure is/was major clunking going into a forward gear (only once....until you put it in reverse, then they clunk again, until you go forward again, et cetera).

_________________
2005 GXP - White Gold Pearl, no mods...yet.
2000 SSEi - Resurrection in progress. Built L67 w/L32 fuel rail, ported heads, and cam. Camaro front brake system, GXP cluster, and much more in planning.

So if it's an axle, is that something I'll be able to tell by checking for excessive play?

I'm thinking of getting an axle on the way home, tearing it down to the diff (might as well with the axle out), checking everything, and replacing the axle.

_________________

95 SLE... a keeper. 241k miles. Low and Slow.
97 BMW 528i
98 Infiniti vq35'd i30: 13.3@104mph, 30MPG Hwy (RIP)
02 Jag X-type
03 BMW M5
05 Chevy Cobalt LS
07 Infiniti G35s 6MT (Sold)
07 Ducati Monster S2R 800 with DS1000 swap
83 Yamaha IT175K
72 Yamaha DS7: '74 RD250 swap, JL chambers

Info on dropping a 92-99: Here.

No, you won't be able to check for excessive play. If there was enough play for you to move it by hand, imagine what it would do with all that power being moved through it and the weight of your car, etc...

If you can move it by hand...that would be REAL bad...

Ok. So it's a shotgun part then.

_________________

95 SLE... a keeper. 241k miles. Low and Slow.
97 BMW 528i
98 Infiniti vq35'd i30: 13.3@104mph, 30MPG Hwy (RIP)
02 Jag X-type
03 BMW M5
05 Chevy Cobalt LS
07 Infiniti G35s 6MT (Sold)
07 Ducati Monster S2R 800 with DS1000 swap
83 Yamaha IT175K
72 Yamaha DS7: '74 RD250 swap, JL chambers

Info on dropping a 92-99: Here.

Not necessarily. You should be able to jack the front and turn both front wheels in neutral for a comparison. If you feel a difference, have someone do it while you have your hands around the boot for the universal (outer joint) and the tripod joint also on that side.

You may not be able to rule out the axle, but you might be able to point a finger at it.

_________________

Click here for mod list for both cars
93 SSEi, 95 SLE (supercharged) 97 Buick LeSabre Limited
PontiacDad at WCBF '04: Cruise control? That's like surrendering!
Comprehensive guide to troubleshooting, rebuilding, and modifying Eaton Superchargers

Hmm...interesting...thanks for the correction...I'll have to write that down next time I have to check my half-shafts.

That technique won't find it for sure, but it could. Keep in mind the dangerous way is to do it on jackstands (rear wheels blocked front and rear) and do it in Drive........goes without saying it'll be spooky and potentially dangerous.

_________________

Click here for mod list for both cars
93 SSEi, 95 SLE (supercharged) 97 Buick LeSabre Limited
PontiacDad at WCBF '04: Cruise control? That's like surrendering!
Comprehensive guide to troubleshooting, rebuilding, and modifying Eaton Superchargers

Mike it sounds more like you are slowly loosing the clutches...

Don, I wouldn't doubt it but it acts the same in at least second and third, maybe first, and the whole worse when turning left thing? Plus WOT is ok?

_________________

95 SLE... a keeper. 241k miles. Low and Slow.
97 BMW 528i
98 Infiniti vq35'd i30: 13.3@104mph, 30MPG Hwy (RIP)
02 Jag X-type
03 BMW M5
05 Chevy Cobalt LS
07 Infiniti G35s 6MT (Sold)
07 Ducati Monster S2R 800 with DS1000 swap
83 Yamaha IT175K
72 Yamaha DS7: '74 RD250 swap, JL chambers

Info on dropping a 92-99: Here.

Have you noticed any slipping? Mine would slip so much it would bounce off the rev limiter in 1st before it would shift to 2nd. Other than that, WOT was fine.

_________________

WHITE WHINE - 1992 SSE Supercharged 236.26 ci (.040 Over) 15.090 at 90.2 MPH on old engine w/ slipping trans & melted O2 sensor - Gen 3 M62 and matching TB, Gen 2 Pully, Zillamotorsports Ported LIM, YT 1.72 Roller Rockers, SII FPR & Injectors, Hypertech Thermomaster chip w/ 160 Thermo, TransGo Shift Kit, Infinity/Pioneer Speakers & a 10" Alpine Type R Sub, all the watts, 140 amp Alternator, Ricepipe CAI w/ heatshield, Pilot Angel Eye Foglights, Clear Corners, '02 17" Chrome Bent 5's, Magnaflow F-Body Muffler and Hi-flo Cat, Ceramic Coated Ported Exhaust Manifolds, Fan Override, Monroe Reflex struts, red calipers
2009 G8 GT - Sport Red Metallic, loaded, SOLO Axlebacks, Rotofab Intake, Tuned, autodim mirror, removed intake manifold cover, HSV GTS triple gauge pod, two tone red-hot shifter and HSV SuperSport steering wheel, GXP rear sway bar and diffuser, 3.45 diff and various Camaro suspension bits, LED Taillights

I forgot to mention it since I'm so use to it, but about 5k ago my trans started slightly thumping into 2nd at mid throttle. If I drive slow it's fine and if I hustle up to the top of the shift in first, take my foot off the gas, let it shift, and continue in second it's fine. This condition hasn't changed in the past 5k.
If I keep on the gas at mid throttle there is a slight hesitation and a small thump into second. The rpms don't shoot up or anything.
Third and fourth are fine and if the trans downshifts under power from second to first, it shifts back into second fine.

_________________

95 SLE... a keeper. 241k miles. Low and Slow.
97 BMW 528i
98 Infiniti vq35'd i30: 13.3@104mph, 30MPG Hwy (RIP)
02 Jag X-type
03 BMW M5
05 Chevy Cobalt LS
07 Infiniti G35s 6MT (Sold)
07 Ducati Monster S2R 800 with DS1000 swap
83 Yamaha IT175K
72 Yamaha DS7: '74 RD250 swap, JL chambers

Info on dropping a 92-99: Here.