DFW Spartan
Well-Known Member
- Messages
- 125
- Location
- Dallas, TX
So one of the first things I was told to do when I bought my T was to install an external transmission cooler, and bypass the internal one in the radiator, due to it commonly failing and taking out the transmission in the process. So it’s been two years now, and I still haven’t gotten around to it. However, after recently reading about several H3/H3T owners with relatively low miles (80K) having their internal transmission coolers recently fail, it’s back on my radar.
On one of the social media H3 groups, a member indicated that most of the trans cooler failures were with the original radiators that came in our trucks (quality issue GM didn’t own up to and issue a recall for), and that later OEM radiators don’t seem to exhibit that same issue. Does anyone know if there’s any truth to that? Multiple automobile manufactures run trans coolers in the radiator (liquid more efficient cooling agent than air), and in fact most manufactures of external trans coolers recommend that you run them in parallel with the internal cooler. I’m just wondering why you hear about the H3/H3T failing so often.
For you folks running aluminum CSF radiators, are you utilizing the internal transmission cooler as designed, or are you also bypassing it with an external trans cooler? I haven’t heard of an aluminum CSF radiator failing for this, but I guess that could be because there are less of them in service.
When I took ownership of my T at 63K miles, the radiator looked relatively new. However I doubt the original owner would have already replaced the radiator at that mileage. I’m currently at 74K miles, and want to get out ahead of anything catastrophic. I’m debating on whether to 1) buy a new OEM radiator for a manual transmission (no internal trans cooler, more radiator cooling surface) and adding an external cooler with thermal bypass, 2) buying a new OEM radiator and running an external trans cooler in parallel with the internal cooler (under the assumption that it was a quality control issue with the original radiator), or 3) buying a CSF radiator and running an external trans cooler in parallel with the internal trans cooler.
There’s something to be said for peace of mind though. For you folks that are running an external trans cooler and bypassing the one in the radiator, any issues with your current set-ups?
Thank you in advance for any and all feedback.
On one of the social media H3 groups, a member indicated that most of the trans cooler failures were with the original radiators that came in our trucks (quality issue GM didn’t own up to and issue a recall for), and that later OEM radiators don’t seem to exhibit that same issue. Does anyone know if there’s any truth to that? Multiple automobile manufactures run trans coolers in the radiator (liquid more efficient cooling agent than air), and in fact most manufactures of external trans coolers recommend that you run them in parallel with the internal cooler. I’m just wondering why you hear about the H3/H3T failing so often.
For you folks running aluminum CSF radiators, are you utilizing the internal transmission cooler as designed, or are you also bypassing it with an external trans cooler? I haven’t heard of an aluminum CSF radiator failing for this, but I guess that could be because there are less of them in service.
When I took ownership of my T at 63K miles, the radiator looked relatively new. However I doubt the original owner would have already replaced the radiator at that mileage. I’m currently at 74K miles, and want to get out ahead of anything catastrophic. I’m debating on whether to 1) buy a new OEM radiator for a manual transmission (no internal trans cooler, more radiator cooling surface) and adding an external cooler with thermal bypass, 2) buying a new OEM radiator and running an external trans cooler in parallel with the internal cooler (under the assumption that it was a quality control issue with the original radiator), or 3) buying a CSF radiator and running an external trans cooler in parallel with the internal trans cooler.
There’s something to be said for peace of mind though. For you folks that are running an external trans cooler and bypassing the one in the radiator, any issues with your current set-ups?
Thank you in advance for any and all feedback.