 Does flat towing hurt, the transaxle? |
|
|
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
|
  |
| Wild 6 |
 Mar 6 2006, 07:19 PM
Post
#1
|
|
See you at the next autocross.  Group: Members Posts: 212 Joined: 16-November 04 From: Phoenix, AZ Member No.: 3,128  |
I had a mechanic tell me that flat towing hurts the transaxle. Specifically, the synchros and bearings. He told me that you need to stop every 100 miles or so and start the car to lubricate the transaxle parts. Is this true?
I have flat towed the car for 100's of miles at a time. Am I screwing up? |
   |
 
|
| Series9 |
Mar 6 2006, 07:24 PM
Post
#2
|
|
Lesbians taste like chicken. Group: Members Posts: 5,444 Joined: 22-August 04 From: DeLand, FL Member No.: 2,602 Region Association: South East States |
With a standard tranny, flat towing will never hurt as long as the shifter isn't loose enough to be bouncing against the shift parts while under way.
|
|
|
|
| iamchappy |
Mar 6 2006, 07:25 PM
Post
#3
|
|
It all happens so fast! Group: Members Posts: 4,893 Joined: 5-November 03 From: minnetonka, mn Member No.: 1,315 Region Association: Upper MidWest  |
I have flat towed my car from Washington to Minnesota still no problems with the transmission and that was 15 years ago.
|
|
|
|
| Series9 |
Mar 6 2006, 07:41 PM
Post
#4
|
|
Lesbians taste like chicken. Group: Members Posts: 5,444 Joined: 22-August 04 From: DeLand, FL Member No.: 2,602 Region Association: South East States |
Look, there's no oil pump in a standard tranny. It's all 'splash' lubrication.
If you're rolling down the road, 'splash' is happening. The tranny has no idea whether or not the engine is running. |
|
|
|
| Aaron Cox |
Mar 6 2006, 07:43 PM
Post
#5
|
||
|
Professional Lawn Dart Group: Retired Admin Posts: 24,541 Joined: 1-February 03 From: OC Member No.: 219 Region Association: Southern California |
yep, im with joe,,, the ring gear is turnin like crazy.... and then the pinion too... so as long as it is rolling it is getting lubed..... (and make sure its outta gear) |
||
|
|
|
||
| bryanc |
Mar 6 2006, 08:04 PM
Post
#6
|
|
Member Group: Members Posts: 321 Joined: 9-August 04 From: San Antonio, Tx Member No.: 2,495 Region Association: Southwest Region |
Another opinion......
The input shaft is not turning though. This means that the bearings that the gears on that shaft are spinning, but not like they do when the power is coming from the input shaft. Furthurmore every other gear on each shaft is turning (i.e. 1,3,5 on the input and 2,4 on the pinion shaft or verse-vicea). It's more or less like driving in 5th gear for several hundred miles without shifting, just a different shaft. An additional difference is that the tranny never gets as warm as it does with the engine running. I don't know if this is good or bad??? Really I don't think it's a bad idea to flat-tow, it does cause wear on the transmission though, but much less stress than the engine does. |
|
|
|
| Series9 |
Mar 6 2006, 08:09 PM
Post
#7
|
|
Lesbians taste like chicken. Group: Members Posts: 5,444 Joined: 22-August 04 From: DeLand, FL Member No.: 2,602 Region Association: South East States |
On a standard tranny, all the gears are constantly meshed. Additionally, the 'input' shaft is constantly turned by the drive axles while in tow. Lubrication fully occurs as it does in normal operation.
Your comment about the oil warming up is true, but inconsequential. |
|
|
|
| DanT |
Mar 6 2006, 08:09 PM
Post
#8
|
|
Going back to the Dark Side! Group: Members Posts: 4,300 Joined: 4-October 04 From: Auburn, CA Member No.: 2,880 Region Association: None |
Direct from a 30+ year factory trained Porsche mechanic....flat towing does not hurt the tranny. As stated previously, splash lubrication during driving or towing.
I know personally many folks that have been flat towing 914s and 911s to and from AXs and Time Trials for many many years with no problems. I am talking everything from fairly stock 2.0L 914s to 2.8L twin plugged and 3.4 twin plugged 915 gear boxed 911s. One of them is running 335 rubber on the rear. Several of these cars have been towed this way for over 15 years. That's it. |
|
|
|
| gregrobbins |
Mar 6 2006, 08:11 PM
Post
#9
|
|
Member: Team NARP Group: Members Posts: 1,515 Joined: 23-March 04 From: Arizona Member No.: 1,844 Region Association: Southwest Region |
There have been threads about this before and the general consensus is that there is no problem. Andy, I just think Bryan wants to see you spend money on a trailer rather than more "go fast" parts. (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)
|
|
|
|
| brp914 |
Mar 6 2006, 08:28 PM
Post
#10
|
|
Unregistered |
I took trans rebuilding at a JC to kill time after work until traffic died down. We took apart cars that have cheapo gear boxes where gears are not mounted on needle bearings like on Porsche. Just gears mounted on shafts. Those types cannot be towed long distances without disaster. But whether the 1 - 3 synchros on a 914 are getting adequately lubed w/o the gears turning is debatable.
|
|
|
|
| Leo Imperial |
Mar 6 2006, 08:32 PM
Post
#11
|
|
Do you have to use so many cuss words? Group: Members Posts: 906 Joined: 29-November 04 From: 914 Roadshow - Glen Cove NY Member No.: 3,192 Region Association: None |
3100 miles and no problem.
I'm also with Joe. |
|
|
|
| bryanc |
Mar 6 2006, 08:37 PM
Post
#12
|
||
|
Member Group: Members Posts: 321 Joined: 9-August 04 From: San Antonio, Tx Member No.: 2,495 Region Association: Southwest Region |
The input shaft to me is the shaft that attaches to the clutch. This does not turn when you are towing unless you are in gear. The pinion shaft does turn. I do agree that the lubrication will work fairly normally, just cooler. |
||
|
|
|
||
| Allan |
Mar 6 2006, 08:39 PM
Post
#13
|
||
|
Teenerless Weenie Group: Members Posts: 8,373 Joined: 5-July 04 From: Western Mesopotamia Member No.: 2,304 Region Association: Southern California |
No... |
||
|
|
|
||
| Wild 6 |
Mar 6 2006, 08:57 PM
Post
#14
|
|
See you at the next autocross. Group: Members Posts: 212 Joined: 16-November 04 From: Phoenix, AZ Member No.: 3,128 |
Thanks for all the input. I have towed this car all over the Southwest and I plan to flat tow it to the PCA California Festival of Speed at the end of the month. I have a small fortune in this gearbox and didn't want to break it.
|
|
|
|
| Joe Bob |
Mar 6 2006, 09:11 PM
Post
#15
|
|
Retired admin, banned a few times Group: Members Posts: 17,427 Joined: 24-December 02 From: Boulder CO Member No.: 5 Region Association: None |
Tell yer wrench to lower his crack intake.....
|
|
|
|
| jimtab |
Mar 6 2006, 09:46 PM
Post
#16
|
||
|
Advanced Member Group: Members Posts: 3,477 Joined: 5-January 03 From: Pacifica, California Member No.: 91 Region Association: Northern California |
nice one Z... (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) |
||
|
|
|
||
| Porcharu |
Mar 6 2006, 10:03 PM
Post
#17
|
|
Senior Member Group: Members Posts: 1,314 Joined: 27-January 05 From: Campbell, CA Member No.: 3,518 Region Association: Northern California |
The transmission is turning just like you are driving down the road, just less stress and strain. However the bearings and such will still wear - just like driving down the road. I would think a synthetic trans oil would be a good thing because the trans is spinning yet the load is tiny so the temp should be low.
|
|
|
|
|
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 16th May 2024 - 03:29 PM |
Invision Power Board
v9.1.4 © 2024 IPS, Inc.