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Bearing Failure vs. Driving in L

  • Have had bearing failure or symptoms and I drive in L more than half the time

    Votes: 15 6.9%
  • Have had bearing failure or symptoms and I drive in L less than half the time

    Votes: 11 5.1%
  • Have Not had bearing failure or symptoms and I drive in L more than half the time

    Votes: 134 61.8%
  • Have Not had bearing failure or symptoms and I drive in L less than half the time

    Votes: 57 26.3%
21 - 34 of 34 Posts
I voted, but, as others have said, I don't see the point. Without accounting for other variables, such as time in service, how is any correlation between 'L' and bearing failure going to mean anything.

Don't you get the same gear lash issue when hitting the brakes? The car is still in regen mode even if not in 'L'.
 
Why the continued focus on D vs. L? Everyone knows it's the daytime running lights that causes this issue. Virtually all those reporting a bad bearing use their DTRL's all or most of the time.

Even though WOT reported GM found the cause to be an assembly error, I can prove it's the DTRL's, perhaps in conjunction with the radio being on :)
 
Discussion starter · #24 ·
I love the trash talk! In forums you can speak like an Design Engineer without having any data at all! :)

There is no where near enough data yet (except in the control group), but if the entrees continue in the same ratios, then we will actually have data showing that driving in L has no correlation to Bearing failure.

I know people with opinions will say they knew that all along, but at least technically oriented people will have some data to back it.
 
Discussion starter · #25 · (Edited)
I voted, but, as others have said, I don't see the point. Without accounting for other variables, such as time in service, how is any correlation between 'L' and bearing failure going to mean anything.

Don't you get the same gear lash issue when hitting the brakes? The car is still in regen mode even if not in 'L'.
This is a good question, in this poll the only controlled variable is the ratio of people driving in l vs d. It is making an assumption that all other variables like time in service and miles are on average the same for people driving in L vs D. I think this should be close, but there could be some dependencies like people that drive in L have more miles or time in service on average than people that drive in D. If this is the case the data will be screwed.
There is a test for this, but it would have to be done after this study is complete. It would require another poll though, and based on the fun this one has created, I'll think I'll pass.

As far as the second question, I have no idea. But so far the data is looking like the answer is no effect of driving in L. Need much more data though.
 
I had the bearing failure about 2 weeks after I bought my Volt. I took it back to the dealership, they gave me a rental, it took three days until they got the part and I had my Volt back. Was it a pain to pay for gas on the rental, yes, but they did a great job on the maintenance and I haven't had any problems since:)

Kenya
Go Blue Volt!
 
I had the bearing failure about 2 weeks after I bought my Volt. I took it back to the dealership, they gave me a rental, it took three days until they got the part and I had my Volt back. Was it a pain to pay for gas on the rental, yes, but they did a great job on the maintenance and I haven't had any problems since:)

Kenya
Go Blue Volt!
Just to help with data collection, can you tell me when you bought your Volt (roughly), and the model year?
 
Discussion starter · #28 ·
statistical status as of 89 respondents.

Because of the shift in population between the test group and the control group, even with the small number of test group respondents (9), some preliminary data can be analyzed.

This poll is reporting that with a 70 percent confidence level driving in L has no negative effects on bearing failure. Meaning that there is now only a 30 percent chance that the continuation of this data collection will result in other conclusions. Now a true Actuary would say I probably just skewed the rest of the study, but for me 70 percent confidence is enough for me to start driving in L.

What the poll can't say with any confidence is wether or not driving in D has adverse effects on bearing failure, but I just wanted to make sure that driving in L does not.

If anyone is interested in the math you can E-mail me, but it's pretty boring stuff. If more people vote over time I will update the confidence levels.
 
GM's explanation was that the cause were a few parts damaged during assembly, resulting in the eventual bearing failure. Slapshot's info appeared to support this, finding no correlation between MY, L, D, miles and the bearing failure. IOW, it appeared to be random and rare.

I hope this finally puts your poll analysis finally puts this Low/Bearing Failure conjecture to rest. Unfortunately, history says otherwise and that 6 months from now we will be dragged through this yet again by someone who feels L is the cause. :)
 
statistical status as of 89 respondents.

Because of the shift in population between the test group and the control group, even with the small number of test group respondents (9), some preliminary data can be analyzed.

This poll is reporting that with a 70 percent confidence level driving in L has no negative effects on bearing failure.
Did you move the one confirmed incorrect vote from "Have had" to "Have NOT had" (http://gm-volt.com/forum/showthread.php?66482-Bearing-Failure-vs-Driving-in-L&p=862498#post862498)? That change may make the case even stronger.
 
Discussion starter · #31 ·
Scary poll almost 12% had bearing failures ????...I am OK ,but my local VOLT mechanic was aware of this problem,,, in >60,,000 VOLTS produced in 5 yrs ,,,did >6.000 had bearing problems ??? I doubt it,,,
People with a Volt problem tend to post, those who don't are rarely heard from. So the validity of any poll on this forum is always suspect. The results are of those who are 1) members 2) who see the poll and 3) actually choose to participate. In addition, most of the reported problems happened in the first few model years and very few with later years. So I doubt it's representative of all model years.
 
I agree with your comment about polls.
Was checking out our forum and ended up here because of bearing MGB failure on our 2012 with 72,000+ miles on it. GM is taking care of the repair, but would hope to understand what caused this condition.
 
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