Hey guys. I have a 2005 and am a proud owner. KNowing it was advanced to a six speed later, i have a question.

I have no issue with the performance and gear ratio of my five speed, even though i am still infatuated with the 7 speeds in my Merz E 550 but other than certain subtle performance and gas mileage differences, are there any known ISSUES with the 5 speed auto v.s. the 6 speed i need to be made aware of? Is it an inferior unit by QUALITY standards to the six, or just in nature of performance. Just curious about your input thanks!

Hey guys. I have a 2005 and am a proud owner. KNowing it was advanced to a six speed later, i have a question.

I have no issue with the performance and gear ratio of my five speed, even though i am still infatuated with the 7 speeds in my Merz E 550 but other than certain subtle performance and gas mileage differences, are there any known ISSUES with the 5 speed auto v.s. the 6 speed i need to be made aware of? Is it an inferior unit by QUALITY standards to the six, or just in nature of performance. Just curious about your input thanks!

I don't know if this is a common issue with the '05, but mine has been to the dealer 4 times in quick succession. No more than a few hundred miles at most between failures. There is a persistent oil leak in the transmission oil pan/trans-axle mating area. It only shows after the car has been sitting for about a week or so. A puddle appears under the transmission pan area.
The dealer has replaced the pan gasket, the shift linkage selector shaft seal and pan drain plug. I have taken pictures of the leaks and traces and sent them to the dealer to help them troubleshoot. It just happened again, so back it goes! This is getting to be annoying to the point where the car is almost no fun anymore...almost.

Well i certainly hope this is the exception and not the rule...but i guess other 04' and 05' owners will chime in if this is something to be aware of ongoing. Hope it all works out and i appreciate the input.

The five speed is fine. The XLR tranny's are French-built in a clean room, so the quality is built in. The six has been reliable as well. The diffs need to have their levels maintained and additives mixed in when the units are flushed or they can get a little noisey.

This was the last (and best) generation of the Northstar. Earlier models were notorious for blown head gaskets due to inserts pulling out. Similar failures are rare for the XLR. Rest assured. Go drive!

CC :seeya

Hi ccclarke my xlr 2005 have around 20,000mil and it will go for winter sleep
do you recommand replace all fluid antifreeze /trany oil/axle/ect...
For next summer because not sur the quality lub inside ??

Regard daniel

A great question Daniel!

The amount of preventive maintenance required for the XLR (and most modern cars) is pretty low, compared to the vehicles we grew up with.

Remember when a car with 100k mi was considered to have one wheel in the auto graveyard? Thankfully, those days are long gone.

Depending if you're the first owner, or have the vehicle's service records available, (you can get them from your dealer if you furnish the VIN) you should have a relatively good idea as to what needs to be done. If in doubt, have the vehicle inspected and replace whatever fluids your mechanic recommends replacing.

I'm a firm believer in "If it works, leave it alone." but I usually temper that with "Trust, but verify." An '05 could be up to seven years old if it were an '04 build, so you're smart to keep the condition of the fluids monitored. 20k mi is pretty low too, so mechanically, your car is barely broken in!

For long-term storage, add fuel stabilizer and drive the car enough to get it fully mixed thoughout the fuel system. A Battery Tender or Minder is another must-have. There's a long-term storage post here on the forum you can check out. As for fluids, I had my cooling system flushed after five years, followed by the differential with friction modifier added. This might be a good time to really get under the hood (and car) to inspect fittings and gaskets for leaks. Lube up the rubber seals (especially around the roof.) There are lots of good products available and everyone has their favorite. GM recommends Krytox (so do a lot of Navy divers) to keep them pliable.

Also check to ensure the rear/left compartment drain is not clogged. Flood that area and you could pay enough for more than two new sets of tires.

To make a long post short, I hope this answers your question. Peace of mind --priceless. For everything else, there's Mastercard!

CC :seeya

Thanks ccclark

i like answer like that .....bumper to bumper :-)
i am the 3 owner last record i see is motor oil change only +
top motor + electric problem fix.

Regard daniel

I've searched the forums and I guess I have the first hard tranny failure of a Base model XLR.

It happened while doing some "SPIRITED DRIVING" at NCH in july.

Symptoms: When auto or manual shifting from 2nd to 3rd gear, the tranny shifts out of 2nd but won't shift into 3rd unless I let off the gas pedal. If I don't let off the gas pedal, the engine over-revs as though I missed 3rd gear in a manual transmission.
There is no problem shifting from 1st to 2nd, 3rd to 4th, 4th to 5th or even down shifting from 5th to 4th for passing.
I drove it from BG, Ky. to my daughter's in Wisconsin and then to Colorado Springs, Co. where I had it checked out at Red Noland Cadillac. They informed me that they would have to replace the tranny and I would have to leave the car there.
I could not do that so I drove it home and replaced the tranny myself.
I was lucky getting a rebuilt replacement tranny from gmpartsdirect.com as they had them on sale for $1,857.07 plus shipping and handling and a refundable $700. core charge.
Here is an interesting fact about this tranny!( P/N; 96042733, aka 5L50-E)
This is the same tranny used in quite a lot of the GM vehicles, i.e. Pontiac, Olds, Buick etc. In other words, it IS NOT a special tranny for the base model XLR. It's been used by GM since about 1975.
I'm not sure about the manual shifting feature, (i.e. Tap, Bomp or Paddle) in the earlier models as that may be the dash difference (-E).

Jack, glad you were able to get home without problems and were able to do the job yourself. I have looked at mine and it looks like a complicated process to remove and replace the transmission.

My 2005 STS also has the 5L50E with about 70,000 miles and it works well so far. The 6L80 used in the V is a much heavier duty transmision also used in the later model 3/4 ton trucks as well as the Hummer. I am not sure if that is the same six speed used in the 2007 to 2009 XLRs or not.

Correction to my earlier post:

The 6-speed transmission (6L80-E) was assembled in Ypsilanti, MI.

Only the five speed (5L50-E) was assembled in Strasbourg, France.

Sorry for any confusion this may have caused.

CC :seeya

I don't know if this is a common issue with the '05, but mine has been to the dealer 4 times in quick succession. No more than a few hundred miles at most between failures. There is a persistent oil leak in the transmission oil pan/trans-axle mating area. It only shows after the car has been sitting for about a week or so. A puddle appears under the transmission pan area.
The dealer has replaced the pan gasket, the shift linkage selector shaft seal and pan drain plug. I have taken pictures of the leaks and traces and sent them to the dealer to help them troubleshoot. It just happened again, so back it goes! This is getting to be annoying to the point where the car is almost no fun anymore...almost.

Well they found that persistent leak. It was the input selector shaft seal. They had replaced it once before, but the new seal leaked. They have since cleaned and "repaired" the shaft and put in another new seal. Dealer kept it for about 2 weeks to ensure the leak did not reappear as it had previously. They said it is not leaking. We picked it up today, let's hope it's a permanent fix this time.
Nice to have it back!

Well now I guess you'll have to test it out with more.....

"It happened while doing some "SPIRITED DRIVING" at NCH in july.". :lol :lol